There’s always a reason to stop and appreciate the smaller stuff in life. Since 2018, Tracy and Dan Calder have drawn attention to documenting daily minutiae with the Close-up Photographer of the Year competition, highlighting the past 12 months’ best images capturing nature, animal, underwater, and human subjects.

The 5th annual edition is no exception, with amazing glimpses of everything from slumbering frogs, to magnetic waves, to microscopic life, to rarely seen deep sea creatures. Across a wide range of categories, photographers around the world managed to snap some extremely striking images, making even some of the creepiest of crawlies look pretty cute for a change. Check out a few of our favorite finalists and winners of 2023 below, and remember to keep an eye out for the little things this year. They’re always there and worth seeing, even if you don’t have a camera in hand.

See more at Cupoty.com.

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Unlike some pretty metal plants that thrive in the darkness, yeast generally doesn’t function well in the light. This fungi turns carbohydrates into ingredients for beer or bread when left to ferment in the dark. It must be stored in dark dry places, as exposure to light can keep fermentation from happening all together. However, a group of scientists have engineered a strain of yeast that may actually work better with light that could give these fungi an evolutionary boost in a simple way. The findings are described in a study published January 12 in the journal Current Biology.

[Related: The key to tastier beer might be mutant yeast—with notes of banana.]

“We were frankly shocked by how simple it was to turn the yeast into phototrophs (organisms that can harness and use energy from light),” study co-author and Georgia Institute of Technology cellular biologist Anthony Burnetti said in a statement. “All we needed to do was move a single gene, and they grew 2 percent faster in the light than in the dark. Without any fine-tuning or careful coaxing, it just worked.”

Giving yeast such an evolutionarily important trait may help us understand how phototropism originated and how it can be used to study evolution and biofuel production, as well as how cells age. 

Give it some energy

Previous work on the evolution of multicellular life by this research group inspired the new study. In 2023, the group uncovered how a single-celled model organism called snowflake yeast could evolve multicellularity over 3,000 generations. However, one of the major limitations to their evolution experiments was a lack of energy.

“Oxygen has a hard time diffusing deep into tissues, and you get tissues without the ability to get energy as a result,” said Burnetti. “I was looking for ways to get around this oxygen-based energy limitation.”

Light is one of the ways organisms can get an energy boost without oxygen. However, from an evolutionary standpoint, an organism’s ability to turn light into usable energy can be complicated. The molecular machinery that allows plants to use light for energy requires numerous proteins and genes that are difficult to synthesize and transfer into other organisms. This is difficult in the lab and through natural processes like evolution. 

A simple rhodopsin

Plants are not the only organisms that can convert light into energy. Some on-plant organisms can also use this light with the help of rhodopsins. These proteins can convert light into energy without any extra cellular machinery.

“Rhodopsins are found all over the tree of life and apparently are acquired by organisms obtaining genes from each other over evolutionary time,” study co-author and Georgia Tech Ph.D. student Autumn Peterson said in a statement. 

[Related: Scientists create a small, allegedly delicious piece of yeast-free pizza dough.]

A genetic exchange like this is called a horizontal gene transfer, where genetic information is shared between organisms that are not closely related. A horizontal gene transfer can cause large evolutionary leaps in a short period of time. One example of this is how bacteria can quickly develop resistance to certain antibiotics. This can happen with all kinds of genetic information and is particularly common with rhodopsin proteins.

“In the process of figuring out a way to get rhodopsins into multi-celled yeast,” said Burnetti, “we found we could learn about horizontal transfer of rhodopsins that has occurred across evolution in the past by transferring it into regular, single-celled yeast where it has never been before.”

Under the spotlight

To see if they could give a single-celled organism a solar-powered rhodopsin, the team added a rhodopsin gene synthesized from a parasitic fungus to common baker’s yeast. This individual gene is coded for a form of rhodopsin that would be inserted into the cell’s vacuole. This is a part of the cell that can turn chemical gradients made by proteins like rhodopsin into needed energy. 

With this vacuolar rhodopsin, the yeast grew roughly 2 percent faster when it was exposed to light. According to the team, this is a major evolutionary benefit and the ease that the rhodopsins can spread across multiple lineages might be key. 

“Here we have a single gene, and we’re just yanking it across contexts into a lineage that’s never been a phototroph before, and it just works,” said Burnetti. “This says that it really is that easy for this kind of a system, at least sometimes, to do its job in a new organism.”

Yeasts that function better in the light could also increase its shelf life. Vacuolar function may also contribute to cellular aging, so this group has started collaborating with other teams to study how rhodopsins may reduce aging effects in the yeast. Similar solar-powered yeast is also being studied to advance biofuels. The team also hopes to study how phototrophy changes yeast’s evolutionary journey to a multicellular organism. 

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Hummingbirds are some of the fastest and most agile birds on Earth. They can squeeze into incredibly small spaces to get nectar and hit flight speeds as high as 9Gs while courting without getting physically hurt. They also appear to have very controlled methods of flight. Hummingbirds use two distinct sensory strategies to control how they fly, depending on whether they are moving forward or hovering. The findings are described in a study published January 10 in the journal Proceedings of the Royal Society B.

[Related: Hummingbirds have two creative strategies for flying through tight spaces.]

When flying forward, hummingbirds rely on an “internal forward model.” This model is an ingrained and intuitive autopilot that allows them to gauge speed while experiencing multiple visual stimuli. 

“There’s just too much information coming in to rely directly on every visual cue from your surroundings,” study co-author and University of British Columbia zoologist and comparative physiologist Vikram B. Baliga said in a statement. 

However, when the birds are hovering or handling cues that may require them to change their altitude, the team found that they use more real-time, direct visuals from their environment. 

To study these flight patterns, the team brought 11 wild adult male Anna’s hummingbirds (Calypte anna) into the lab. They prompted the birds to repeatedly fly from a perch to a feeder in a tunnel about 13 feet long and recorded videos of each flight. The team also projected patterns on the front and side walls of the tunnel to test how the hummingbirds reacted to this variety of visual stimuli.

In some flight scenarios, the researchers projected vertical stripes that were moving along at various speeds on the side of the tunnel to mimic forward motion. Other times, they used horizontal stripes on the side to mimic a change in altitude. On the front wall, the team projected  rotating swirls. These circular patterns were designed to create the illusion of a change in position.

“If the birds were taking their cues directly from visual stimuli, we’d expect them to adjust their forward velocity to the speed of vertical stripes on the side walls,” said Baliga. “But while the birds did change velocity or stop altogether depending on the patterns, there wasn’t a neat correlation.”

However, the team observed that the hummingbirds adjusted more directly to stimuli indicating a change in altitude while they were flying. When the birds were hovering, they also worked to adjust their position so they were closer to the shifting spirals on the front wall. 

[Related: This hybrid hummingbird’s colorful feathers are a genetic puzzle.]

“Our experiments were designed to investigate how hummingbirds control flight speed,” study co-author and University of British Columbia zoologist and comparative physiologist Doug Altshuler said in a statement. “But because the hummingbirds took spontaneous breaks to hover during their flights, we uncovered these two distinct strategies to control different aspects of their trajectories.”

The findings provide insight on how these speedy birds perceive the world when they transition their flight patterns. Data like this could also help engineers develop better onboard navigation systems for drones and hovering vehicles in the future.

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Beginning about 2.6 million years ago, giant primates almost 10 feet tall weighing 551 pounds roamed the plains of southern China. Gigantopithecus blacki (G. blacki) towered over today’s largest monkeys by about five feet and is believed to be the largest primate to ever roam the Earth. However, it went extinct just as other primates–like orangutans–were thriving. 

[Related: These primate ancestors were totally chill with a colder climate.]

Now, a team of scientists from China, Australia, and the United States believe that this giant ape went extinct between 295,000 and 215,000 years ago because it could not adapt its food preferences and behaviors and was vulnerable to extreme changes in the planet’s climate. The findings are detailed in a study published January 10 in the journal Nature. 

“The story of G. blacki is an enigma in paleontology–how could such a mighty creature go extinct at a time when other primates were adapting and surviving? The unresolved cause of its disappearance has become the Holy Grail in this discipline,” Yingqi Zhang, study co-author and Institute of Vertebrate Palaeontology and Palaeoanthropology at the Chinese Academy of Sciences (IVPP) paleontologist, said in a statement. 

Seasonal shifts 

Roughly 700,000 to 600,000 years ago, the rich forest environment that G. blacki lived in began to change. The new study proposes that as Earth’s four seasons began to strengthen and G. blacki’s habitat saw more variability in temperature and precipitation, the structure of these forest communities began to change. 

In response, G. blacki’s close relatives the orangutans adapted their habitat preferences, behavior, and size over time. However, G. blacki was not quite as nimble. Based on its dental anatomy, these giant apes were herbivores that had adapted to eat fibrous foods like fruits. However, when its favorite food sources were not available, the team believes that G. blacki relied on a less nutritious backup source of sustenance, decreasing the diversity of its food. They likely suffered from a reduced geographic range for foraging, became less mobile, and saw chronic stress and dwindling numbers. 

“G. blacki was the ultimate specialist, compared to the more agile adapters like orangutans,  and this ultimately led to its demise,” said Zhang. 

Honing in on a date

G. blacki left behind roughly 2,000 fossilized teeth and four jawbones that helped paleontologists put together the story of G. blacki’s time on Earth, but more precise dating of these remains was needed to determine its extinction story. To find definitive evidence of their extinction, the team took on a large-scale project that explored 22 cave sites in a wide region of Guangxi Province in southern China. 

[Related: Nice chimps finish last—so why aren’t all of them mean?]

Determining the exact time when a species disappears from the fossil record helps paleontologists determine a timeframe that they can work to rebuild from other evidence. 

“Without robust dating, you are simply looking for clues in the wrong places,” Kira Westaway, a study co-author and geochronologist at Macquarie University in Australia, said in a statement

In the study, the team used six dating techniques the samples of cave sediments and teeth fossils. The techniques produced 157 radiometric ages that were combined with eight sources of environmental and behavioral evidence. They took this combined figure and applied it to 11 caves that had evidence of G blacki in them and 11 caves of a similar age range that did not have any remains of G. blacki.

The primary technique that helped the team hone in on a date range was luminescence dating. It measures a light-sensitive signal that is found in the burial sediments that encased the G. blacki fossils. Uranium series and electron-spin resonance were also critical in dating the G. blacki teeth themselves. 

“By direct-dating the fossil remains, we confirmed their age aligns with the luminescence sequence in the sediments where they were found, giving us a comprehensive and reliable chronology for the extinction of G. blacki,” Renaud Joannes-Boyau, a study co-author and geochronologist at Southern Cross University  in Australia, said in a statement. 

Building a world from teeth and pollen 

Researchers also used a detailed pollen analysis to reconstruct what the plant life looked like hundreds of thousands of years ago, a stable isotope analysis of the teeth, and a detailed analysis of the cave sediments to re-create the environmental conditions leading up to the time G blacki went extinct. Trace element and dental microwear textural analysis of the apes’ teeth enabled the team to model what G. blacki’s behavior likely looked like when they were flourishing, compared to their demise. 

[Related: An ‘ancestral bottleneck’ took out nearly 99 percent of the human population 800,000 years ago.]

“Teeth provide a staggering insight into the behavior of the species indicating stress, diversity of food sources, and repeated behaviors,” said Joannes-Boyau.

The dates of the fossils combined with the pollen and teeth analysis revealed that G.blacki went extinct between 295,000 and 215,000 years ago, earlier than scientists previously assumed. The team believes that studying their lack of adaptation has implications for today’s changing climate and the need for adaptation. 

“With the threat of a sixth mass extinction event looming over us, there is an urgent need to understand why species go extinct,” said Westaway. “Exploring the reasons for past unresolved extinctions gives us a good starting point to understand primate resilience and the fate of other large animals, in the past and future.”

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Some fruit bats eat up to twice their body weight in sugary mangoes, bananas, or figs every day to not only survive, but thrive. Unlike humans, these flying mammals can have an essentially permanent sweet tooth and do not develop some of the negative health consequences such as diabetes. A study published January 9 in the journal Nature Communications found that genetic adaptations have helped keep their sugary diets from becoming harmful. 

[Related: How do bats stay cancer-free? The answer could be lifesaving for humans.]

The study could have future implications for treating diabetes, which affects an estimated 38 million Americans, according to the Centers for Disease Control and Prevention (CDC). It is the eighth leading cause of death in the United States and the leading cause of kidney failure, lower-limb amputations, and adult blindness.

“With diabetes, the human body can’t produce or detect insulin, leading to problems controlling blood sugar,” study co-author and University of California, San Francisco geneticist Nadav Ahituv said in a statement. “But fruit bats have a genetic system that controls blood sugar without fail. We’d like to learn from that system to make better insulin-or sugar-sensing therapies for people.”  

Fruit bats vs. insect bats

Every day, fruit bats wake up after about 20 hours of sleep and feast on fruit before returning back to their caves, trees, or human-built structures to roost. To figure out how they can eat so much sugar and thrive, the team in this study focused on how the bat pancreas and kidneys evolved. The pancreas is an abdominal organ that controls blood sugar. 

Researchers compared the Jamaican fruit bat with an insect-eating bat called the big brown bat. They analyzed the gene expression–which genes were switched on or off–and regulatory DNA that controls gene expression. To do this, the team measured both the gene expression and regulatory DNA present in individual cells. These measurements show which types of cells primarily make up the bat’s organs and also how these cells regulate the gene expression that manages their diet. 

They found that the compositions of the pancreas and kidneys in fruit bats evolved to accommodate their sugary diet. The pancreas had more cells to produce insulin, an essential hormone that tells the body to lower blood sugar. It also had more cells that produce another sugar-regulating hormone called glucagon. The fruit bat kidneys had more cells to trap scarce salts and electrolytes as they filter blood.  

Changes in DNA

Taking a closer look at the genetics behind this, the team saw that the regulatory DNA in those cells had evolved to switch the appropriate genes for fruit metabolism on or off. The insect-eating big brown bats had more cells that break down protein and conserve water and the gene expression in these cells was calibrated to handle a diet of bugs. 

[Related: Vampire bats socially distance when they feel sick.]

“The organization of the DNA around the insulin and glucagon genes was very clearly different between the two bat species,” study co-author and Menlo College biologist Wei Gordon said in a statement. “The DNA around genes used to be considered ‘junk,’ but our data shows that this regulatory DNA likely helps fruit bats react to sudden increases or decreases in blood sugar.” 

While some of the fruit bat’s biology resembled what is found in humans with diabetes, the bats are not known to have the same health effects.

“Even small changes, to single letters of DNA, make this diet viable for fruit bats,” said Gordon. “We need to understand high-sugar metabolism like this to make progress helping the one in three Americans who are prediabetic.” 

Studying bats for human health

Bats are one of the most diverse families of mammals and everything from their immune systems to very particular diets are considered by some scientists to be examples of evolutionary triumph. This study is one of recent examples of how studying bats could have implications for human health, including in cancer research and virus prevention. 

For this study, Gordon and Ahituv traveled to Belize to participate in an annual Bat-a-Thon, where they took census of wild bats and field samples. One of the Jamaican fruit bats that they captured at the Bat-a-Thon was used to study sugar metabolism.  

“For me, bats are like superheroes, each one with an amazing super power, whether it is echolocation, flying, blood sucking without coagulation, or eating fruit and not getting diabetes,” Ahituv said. “This kind of work is just the beginning.” 

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When it’s time for a snack, the miniscule sea creature known as Oikopleura dioica gets gross. At barely a millimeter long, the filter-feeding larvacean excretes and encases itself in a jelly-like substance to form what biologists dub a “mucus house” or a “snot palace.” 

A tadpole-like O. dioica’s tiny, temporary abodes are biological wonders—using its tail, the larvacean creates its own pump-filtration system capable of capturing and propelling food particles towards its mouth. Now, researchers believe the snot palace’s interior fluid dynamics could inspire a new generation of artificial pump systems for wastewater treatment plants and air filtration systems.

[Related: These animals build palaces out of their own snot.]

“It’s so cool. It’s a pretty complex structure,” University of Oregon biology research assistant Terra Hiebert said in a January 8 profile.

Hiebert and collaborators detailed their work in a study recently published in the Journal of the Royal Society Interface. To better understand a snot palace’s inner workings, Hiebert’s team traveled to a larvacean breeding facility in Bergen, Norway to analyze the creatures’ movements using a high-speed video camera attached to a microscope. In reviewing the footage, researchers noticed how an O. dioica’s tail shifted responsibilities depending on whether or not it was time to eat. While simply swimming near the ocean’s surface, the tail wriggles side-to-side to push the creature forward through water, but it’s a different story once inside the mucus house.

Once encased in the gelatinous substance, O. dioica’s appendage actually touches the interior in multiple locations. When the tail wiggles in these moments, the animal doesn’t move nearly as much. Instead, the tail sticks and unsticks from the casing “like Velcro,” according to the University of Oregon, and the snot palace subsequently inflates like a balloon as nearby particles collect on the surface. Each movement pushes these particles along, eventually in the direction of the larvacean’s mouth. Once the mucus filtration system is too clogged to function, O. dioica simply sheds its makeshift restaurant, which then sinks into the ocean and eventually decomposes. In approximately 3-to-4 hours, the larvacean repeats the process all over again.

Although O. dioica’s structure fits the bill for a peristaltic pump, it’s not the most common design. Usually, a peristaltic pump’s fluid motion originates through external pressure, such as contractions in your colon to push along waste. In a snot palace, however, the momentum derives from within the pump itself via the larvacean’s tail. Researchers believe designers could adapt this alternative setup for engineering new wastewater treatment plants or air filtration systems—hypothetically, locating any moving parts within the pump could protect the overall setup from wear-and-tear.

If this proves true, urban planners could have snot palaces to thank for cleaner, more efficient municipal water facilities. 

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Every animal must urinate to get rid of liquid waste in their body. While the pee of a healthy person has a distinctly yellow color, it’s been unclear to scientists for centuries what actually gives urine this hue. Now, a team from the University of Maryland and National Institutes of Health believe that they have solved this mystery by pinpointing the microbial enzyme that makes our pee yellow. The findings are detailed in a study published January 3 in the journal Nature Microbiology.

[Related: Renaissance-era doctors used to taste their patients’ pee.]

According to study co-author and University of Maryland microbiologist Brantley Hall, the team built on decades of research going back to the 1960s and a difficult three-and-a-half-year long lab experiment to find that an enzyme in the gut microbiome called bilirubin reductase is responsible for urine’s color.

“The gut microbiome is just full of incredible chemists. It’s so important to human physiology, all these molecules that the gut microbes are making,” Hall tells PopSci. “As we understand more about microbial chemistry in our gut, we’re going to understand the important things. But the first step for any of this is to figure out the enzymes responsible. If you don’t know what’s going on, you basically can’t even start with the research.”

Solving a microbial mystery 

Previously, scientists knew that the yellow color comes from how the body gets rid of old blood cells. Red blood cells typically reach the end of their life cycle after about 120 days and they are degraded in the liver. A byproduct of this process called bilirubin is a bright orange substance that is secreted from the liver and into the gut. Bacteria living in the gut then convert bilirubin into a colorless substance called urobilinogen. The urobilinogen is finally degraded into the yellow pigment molecule called urobilin that plays a part in the coloring. What scientists did not know was the bacterial enzyme responsible. 

Identifying this enzyme has long been a microbial mystery for two primary reasons. According to Brantley, the first challenge is that culturing anaerobic microbes has historically been very difficult and expensive to do in the lab.

“The microbes that perform this function cannot live with atmospheric oxygen. They die within minutes or seconds,” says Hall. “And those definitely never grow.”

Brantley and the team were able to harness scientific advances made over the past 15 years in culturing these microbes that survive and thrive without oxygen.

The second challenge has been the lack of genome sequences of the microbiomes in the gut. Recent improvements in genetic sequencing means that there were more sequences available for the team to study to see how the microbes in the gut work. 

“In our case, we identified microbes that reduced bilirubin and microbes that did not. And then we performed a comparative genomics analysis between the two and identify candidate genes,” says Hall.

Into the gut microbiome

In the study, the team compared the genomes of the exact species of human gut bacteria that convert bilirubin into urobilinogen with the species of gut bacteria that can’t. This helped them identify the specific gene that encodes bilirubin reductase. Next, they used Escherichia coli (E. coli) to test if this enzyme could convert bilirubin into urobilinogen in it as well as in other gut bacteria.

After searching for this gene in all known bacterial species, the team found that the enzyme is primarily produced by a species belonging to a large group of bacteria that dominate the gut microbiome called Firmicutes. After genetically screening the gut microbiomes of over 1,000 adults to find the pee coloring gene, they found that 99.9 percent of people have gut bacteria that carry the gene for bilirubin reductase. 

[Related: Bees make more friends when they’re full of healthy gut bacteria.]

“I think the biggest surprise to me is how prevalent this function is in adult humans,” says Hall. “Basically, everyone’s urine is yellow, and everyone’s stool is brown, so we knew that there must be microbes that did it. There are actually not that many microbes that do it and they’re essentially prevalent in every person.”

Potential medical applications

The study also looked to see if this gene was present in adults with inflammatory bowel disease (IBD) and infants with jaundice. Only about 68 percent of those with IBD had the gene and about 40 percent of babies under three months old who were at a heightened risk for jaundice. While more research is needed, identifying what these enzymes and genes could help develop better treatments for IBD, jaundice, and even gallstones.

“People are so excited about gut health and I just love talking to people about gut health,” says Hall. “Everyone either has or knows someone who has gut issues and I just think there’s an enormous opportunity to really modulate the human gut microbiome and health in a positive way.”

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The nearly half a billion year old remains of some enormous and extinct carnivorous worms have been discovered near the top of the world by an international team of researchers. The ancient creature named Timorebestia, or ‘terror beasts’ in Latin, lived in the water column of North Greenland over 518 million years ago. The new fossils indicate that the worms had fins on the sides of their bodies, a head with a long antenna, and enormous jaw structures on the insides of their mouth. They could grow to almost 12 inches long. These were some of the largest swimming animals of the Early Cambrian period and are described in a study published January 3 in the journal Science Advances.

[Related: A three-eyed organism roamed the seas half a billion years ago.]

An ‘explosion’ of life

When these terror beasts were alive over 500 million years ago, the Earth was undergoing a major expansion of life called the Cambrian Explosion. This is when most major groups of animals first appear in the fossil record, partially due to cooler temperatures and tectonic changes. All of this biological diversification also occurred in a relatively short period of time–in about 30 million years. 

The Timorebestia fossils were found during a 2017 expedition to the Early Cambrian Sirius Passet fossil locality in a very remote section of North Greenland. Timorebestia may be some of the earliest carnivorous animals to have colonized the water column here and reveal a past potential dynasty of predators that were previously unknown to scientists. Early arthropods were known to be the dominant predators during the Cambrian period, including some “weird shrimp from Canada” called anomalocaridids.

“Our research shows that these ancient ocean ecosystems were fairly complex with a food chain that allowed for several tiers of predators,” study co-author and University of Bristol paleontologist Jakob Vinther said in a statement. “Timorebestia were giants of their day and would have been close to the top of the food chain. That makes it equivalent in importance to some of the top carnivores in modern oceans, such as sharks and seals back in the Cambrian period.”

Timorebestia is also a distant but close relative of living arrow worms called chaetognaths. These worms are much smaller than today’s enormous ocean predators and only eat zooplankton, a far cry from their apex predator days of the past.

Opening a 518 million-year old digestive system 

The fossils from the Sirius Passet were exceptionally well preserved so the team was able to study the remains of their muscle anatomy, nervous systems, and digestive systems very closely. When they looked inside Timorebestia’s fossilized digestive system, they found the remains of a common, swimming arthropod called Isoxys. 

“We can see these arthropods was a food source [for] many other animals,” study co-author and University of Bristol paleontologist Morten Lunde Nielsen said in a statement. “They are very common at Sirius Passet and had long protective spines, pointing both forwards and backwards. However, they clearly didn’t completely succeed in avoiding that fate, because Timorebestia munched on them in great quantities.”

While arthropods like Isoxys appear in the fossil record about 521 to 529 million years ago, modern living arrow worms can be traced back at least 538 million years. Since arrow worms and these more early Timorebestia were swimming predators, the team believes that they dominated the oceans before arthropods took off. Their dynasty may have lasted about 10 to 15 million years before they were superseded by other groups of marine predators. 

Jaw predator evolution

The discovery of Timorebestia is also helping paleontologists understand where jawed predators came from. The arrow worms living today have bristles on their heads for catching prey, instead of having jaws inside of its head like Timorebestia. By comparison, today’s microscopic jaw worms have an oral setup that is more similar to Timorebestia, so arrow worms and jaw worms likely shared an ancestor over half a billion years ago.Timorebestia and some of the other specimens that the team found on this expedition are revealing the evolutionary links between organisms that may look different, but are closely related. It is also helping paint a better picture of how arrow worms evolved over hundreds of millions of years. 

[Related: A 500-million-year-old sea squirt is the evolutionary clue we need to understand our humble beginnings.]

“Living arrow worms have a distinct nervous center on their belly, called a ventral ganglion. It is entirely unique to these animals,” study co-author and Korean Polar Research Institute paleontologist Tae Yoon Park said in a statement. “We have found this preserved in Timorebestia and another fossil called Amiskwia. People have debated whether or not Amiskwia was closely related to arrow worms, as part of their evolutionary stem lineage. The preservation of these unique ventral ganglia gives us a great deal more confidence in this hypothesis.”

The team collected a wide variety of organisms during the expedition and plan to continue to study these specimens to learn more about how the planet’s earliest animal ecosystems evolved. 

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In order to eat, Matabele ants have to fight with their one and only food source: termites. These pre-meal encounters often lead to dangerous injuries from a termite’s fierce mandibles, which can pierce the ants with rapid blows. However, these ants have developed their own saliva-based system to treat their fellow ant’s injuries. New research has found that Matabele ants may even be able to tell if a wound is infected or not and then treat the infected wounds with the antibiotics produced in their saliva. The findings are described in a study published in the journal Nature Communications on December 29, 2023. 

[Related: Ants’ brains are surprisingly good at communicating danger to others.]

A necessary and risky meal

Matabele ants are found in regions south of the Sahara desert in Africa. They can be close to one inch long and are one of the largest known ants on Earth. The termites that they rely on for sustenance often inflict life-threatening injuries on the ants. Up to 22 percent of ants can lose one or more of their legs during these encounters over the course of their foraging lives. Injured ants are even sometimes carried back to the nest by their fellow ants for recovery. 

According to the team on this study, the main cause of death for the ants is an infection from the bacterium Pseudomonas aeruginosa (P. aeruginosa). The ants have been observed treating wounds with P. aeruginosa more frequently. 

Mammals including dogs and bats have molecules in their saliva that potentially have healing properties and are known to lick wounds in an effort to possibly curb the growth of bacteria. The team believes that while other animals have an instinct to lick their wounds, they don’t actually know if they have an infection. However, Matabele ants may have a more discriminating brain and can tell if the wound requires treatment due to specific changes in the chemical profile of an infected wound versus an uninfected wound. 

Studying the saliva

In the study, researchers analyzed the chemical composition of the Matabele ants’ saliva in a lab. For an infected wound, the insects are possibly applying saliva that has antimicrobial compounds and proteins. These antibiotics are taken from their metapleural gland, which is found on the side of their thorax. The secretion has 112 components and half of them are known to have antimicrobial or wound-healing effects. These molecules likely take a lot of energy to produce, so it is helpful for the ants to detect if P. aeruginosa and potentially other threatening bacteria that is common in the soils where Matabele ants live are present before they start to put in the work to produce these compounds. 

When the team applied soil from these areas to wounded and infected Matabele ants, the bacterial loads increased in only two hours at both the wound site and the ants’ thoraxes. This suggested that the ants could recognize changes in the chemical profile of the wound.

[Related: Army ants could teach robots a thing or two.]

“Chemical analyses in cooperation with JMU [Julius-Maximilians-Universität] Professor Thomas Schmitt have shown that the hydrocarbon profile of the ant cuticle changes as a result of a wound infection,” Erik Frank, a study co-author and animal ecologist at Julius-Maximilians-Universität Würzburg in Germany said in a statement. “With the exception of humans, I know of no other living creature that can carry out such sophisticated medical wound treatments.”

To test this further, some of the infected ants were placed in isolation away from their nestmates. Among this group, 90 percent of them died within 36 hours. However, the mortality rate dropped to 22 percent among a group of wounded ants that returned to their colony instead of going to isolation. Ants that were injured but not infected had similar survival rates regardless of being alone or back with the colony. 

The team found that the death rate of infected insects is reduced by about 90 percent after the saliva therapy was applied. They also found that the secretions were deposited significantly more often on the ants with infected wounds than on the insects with sterile wounds. 

The researchers hope to explore more to learn just how unique the Matabele ants are in respect to their wound care behaviors. The study notes that P. aeruginosa is a leading cause of combat wounds in humans, and the team would like to further identify and analyze the antibiotics in Matabele ant saliva with other chemistry research groups. This could lead to the discovery of new antibiotics, as antibiotic resistance continues to grow. 

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An unusual jellyfish species found in the eastern Pacific Ocean called Cladonema pacificum is only about the size of a pinkie nail, but it can regenerate an amputated tentacle in just two or three days. Jellyfish need their tentacles to hunt and feed, so keeping them intact is crucial to their survival. How jellyfish form the parts necessary to regrow appendages has been a mystery. Now, a team based in Japan is beginning to understand the cellular processes that these tiny jellyfish use in limb regeneration. The findings are described in a study published December 21 in the journal PLOS Biology.

[Related: Even without brains, jellyfish learn from their mistakes.]

Finding the blastema

Salamanders and insects like beetles form a clump of undifferentiated cells that have not developed into specific cell types yet. These undifferentiated cells can grow into a blastema, which is critical for repairing damage and regrowing appendages. 

To look for signs of the crucial blastema in jellyfish, the authors of this study amputated a tentacle from a Cladonema pacificum jellyfish in the lab. They then studied the cells that were growing in the jellyfish post-amputation. The team found that jellyfish have stem-like proliferative cells actively growing and dividing, but are not yet changing into specific cell types. These cells appear at the site of injury and help from the blastema.

“Importantly, these stem-like proliferative cells in blastema are different from the resident stem cells localized in the tentacle,” study co-author and University of Tokyo cell biologist Yuichiro Nakajima said in a statement. “Repair-specific proliferative cells mainly contribute to the epithelium—the thin outer layer—of the newly formed tentacle.”

These resident stem-like cells near the jellyfish’s tentacle are responsible for maintaining and repairing whatever cells the jellyfish needs throughout its life. However, the proliferative cells needed to repair a missing appendage only appear when the jellyfish is injured.

“Together, resident stem cells and repair-specific proliferative cells allow rapid regeneration of the functional tentacle within a few days,” Nakajima said. 

Bilaterians vs. non-bilaterians

According to the authors, this finding helps researchers better understand how blastema formation differs among different animal groups who have different developmental shapes. For example, salamanders are bilaterian animals that develop two equal sides on the right and left. Jellyfish are considered non-bilaterians, but both jellyfish and salamanders are capable of regenerating limbs despite their symmetrical differences. Salamander limbs have stem cells restricted to specific cell-type needs and this process appears to operate similarly to the repair-specific cells the team observed in jellyfish.

[Related: There’s no stopping this immortal jellyfish.]

“Given that repair-specific proliferative cells are analogues to the restricted stem cells in bilaterian salamander limbs, we can surmise that blastema formation by repair-specific proliferative cells is a common feature independently acquired for complex organ and appendage regeneration during animal evolution,” University of Tokyo cell biologist Sosuke Fujita said in a statement.

It is still unclear where the repair-specific proliferative cells observed in the blastema originate. The research tools that are currently available to investigate these cellular origins are too limited to explain the source of these cells or find other stem-like cells. More study and new tools for studying genetics are needed. 

“It would be essential to introduce genetic tools that allow the tracing of specific cell lineages and the manipulation in Cladonema,” Nakajima said. “Ultimately, understanding blastema formation mechanisms in regenerative animals, including jellyfish, may help us identify cellular and molecular components that improve our own regenerative abilities.”

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The hedgehog family tree is ending 2023 by getting a few more branches. A study published December 21 in the Zoological Journal of the Linnean Society identified five new species of soft-furred hedgehogs native to Southeast Asia that were found with the help of some DNA analysis and some decades-old museum specimens.

[Related: Why Danish citizen scientists were on a quest to find the oldest European hedgehog.]

Fur instead of spines

Soft-furred hedgehogs–or gymnures–are tiny mammals that are members of the hedgehog family. Instead of being covered in spines like other hedgehogs, they have soft fur. Hedgehogs are not rodents and they have a pointy snout like their relatives. Previously, scientists believed that there were only two species, but this new study increased that number to seven. 

These newly-identified species belong to a group of soft-furred hedgehogs called Hylomys that live in Southeast Asia. Two of the hedgehogs are entirely new species of soft-furred hedgehog. They are named Hylomys vorax and Hylomys macarong and both are endemic to an endangered and incredibly biodiverse tropical rainforest in North Sumatra and Southern Vietnam called the Leuser ecosystem. 

H. macarong has dark brown fur and is about 5.5 inches long. It was named for a Vietnamese word for vampire–Ma cà rồng–since the males have fang-like incisors. Further field study is needed to figure out what these fangs do, but their larger size suggests that it could have a role in sexual selection. The males also have rust-colored chest markings that may have been stained by scent glands.

H. vorax is slightly smaller at 4.7 inches long and also has dark fur. It has a black tail and a very narrow snout. It is believed to only be found on the slopes of Mount Leuser in Northern Sumatra. It was named after a description made by mammalogist Frederick Ulmer, who collected the specimens during an expedition to Sumatra in 1939. Ulmer identified it as a type of shrew in his field notes.

“They were voracious beasts often devouring the whole bait before springing the trap,” Ulmer wrote. “Ham rind, coconut, meat, and walnuts were eaten. One shrew partially devoured the chicken head bait of a steel trap before getting caught in a nearby Schuyler trap baited with ham rind.”

The other three have been promoted from subspecies up to species. A subspecies is a smaller group within a species. They are genetically distinct from other groups within that same species, but can still interbreed and produce viable offspring. These three were initially considered to be a subspecies of Hylomys suillus, but the study found enough genetic and physical differences for them to be upgraded to species. They are named Hylomys dorsalis, Hylomys peguensis and Hylomys maxi.

H. dorsalis lives in Northern Borneo’s mountains and has a dark stripe on its head that bisects its back. 

H. peguensis is only 5.1 inches long with more yellow fur and can be found in many countries in mainland Southeast Asia.

True to its name, H. maxi is also on the larger end of the new species of soft-furred hedgehogs at 5.5 inches and can be found in mountainous regions on the Malay Peninsula and in Sumatra.

According to study co-author and evolutionary biologist Arlo Hinckley, soft-furred hedgehogs generally look more like a mixture between a mouse and a shrew, since they do not have the spines of their cousins’ spines. These small mammals are generally active during both the day and night and are omnivores. They likely eat a wide variety of insects and other invertebrates, and fruit if it is available. 

“Based on the lifestyles of their close relatives and field observations, these hedgehogs likely nest in hollows and take cover while foraging among tree roots, fallen logs, rocks, grassy areas, undergrowth and leaf litter,” Hinckley said in a statement. “But, because they’re so understudied, we are limited to speculate about the details of their natural history.” 

Hinckley is a postdoctoral fellow at the National Museum of Natural History in Washington DC and the University of Seville in Spain. 

Digging in museum drawers 

During his doctoral studies in 2016, Hinckley became interested in the soft-furred hedgehogs. After studying them in Borneo with study co-author Miguel Camacho Sánchez, their early genetic data and studies of many known populations in Southeast Asia suggested that there may be more species than scientists currently recognize. They began to search through natural history collections in search of specimens assigned to this group. Many soft-furred hedgehogs were only preserved skins and skulls.

[Related: Why preserving museum specimens is so vital for science.]

“We were only able to identify these new hedgehogs thanks to museum staff that curated these specimens across countless decades and their original field collectors,” said Hinckley. 

The H. vorax specimen was from the Smithsonian’s collection and sat in a drawer for 84 years. H. macarong spent the last 62 years at the Academy of Natural Sciences of Drexel University in Philadelphia. Hinckley and the study’s co-authors from institutions in the United States, Switzerland, Singapore, Spain, and Malaysia ultimately assembled 232 physical specimens and 85 tissue samples from across the Hylomys group. They made detailed physical observations of and collected measurements to determine the differences in size and shape of skulls, teeth, and their fur.

They then started the genetic analysis at the Doñana Biological Station’s ancient DNA laboratory in Spain and the Smithsonian’s Laboratories of Analytical Biology. The results identified seven distinct genetic lineages and indicated that the number of recognized species in the group was about to increase.

[Related: A key to lizard evolution was buried in a museum cupboard for 70 years.]

“It might be surprising for people to hear that there are still undiscovered mammals out there,” Hawkins said. “But there is a lot we don’t know—especially the smaller nocturnal animals that can be difficult to tell apart from one another.”

The team hopes that describing these new species can expand scientific understanding and be used to conserve threatened habitats such as Northern Sumatra’s Leuser ecosystem. This region faces threats from logging, mining, the fragmentation of forests by road projects, and climate change. 

“This kind of study can help governments and organizations make hard choices about where to prioritize conservation funding to maximize biodiversity,” Hinckley said.

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Frogs are well known for their sticky, whip-like tongues, lumpy warts, and the colorful, poisonous skin covering some species. One group of frogs in Southeast Asia has another distinguishing feature–fangs. Scientists recently discovered a new species of fanged frog that uses these bony jaws jutting out of their lower jawbone to fight with other frogs and hunt shelled prey like giant centipedes and crabs. Limnonectes phyllofolia is also the smallest known species of fanged frog and is described in a study published December 20 in the journal PLOS ONE.

[Related: Female frogs appear to play dead to avoid mating.]

“This new species is tiny compared to other fanged frogs on the island where it was found, about the size of a quarter,” study co-author and biologist Jeff Frederick said in a statement. “Many frogs in this genus are giant, weighing up to two pounds. At the large end, this new species weighs about the same as a dime.” Frederick is a postdoctoral researcher at the Field Museum in Chicago and conducted this research as a doctoral candidate at the University of California, Berkeley.

The frogs were found on the mountainous island of Sulawesi in Indonesia. It’s a large 71,898 square mile-long island with a large network of volcanoes, mountains, lowland rainforest, and cloud forests in the mountains.

“The presence of all these different habitats mean that the magnitude of biodiversity across many plants and animals we find there is unreal—rivaling places like the Amazon,” said Frederick.

Members of a joint United States-Indonesia amphibian and reptile research team noticed something surprising on the leaves of tree saplings and moss-covered boulders in the jungle–frog eggs.

Frogs lay eggs covered by a jelly-like substance instead of a hard and protective shell like a bird. To keep them from drying out, most amphibians will lay their eggs in water. Instead, these frogs left their egg masses on leaves and mossy boulders above the ground. After finding these nests, the team began to see the small, brown frogs. 

“Normally when we’re looking for frogs, we’re scanning the margins of stream banks or wading through streams to spot them directly in the water,” Frederick says. “After repeatedly monitoring the nests though, the team started to find attending frogs sitting on leaves hugging their little nests.” 

The close contact with the eggs allows the adults to coat them with the right compounds to keep them moist and safe from bacterial and fungal contamination. They were named Limnonectes phyllofolia, which translates to “leaf-nester.”

[Related: Go (virtually) adopt an axolotl, the ‘Peter Pan’ of amphibians.]

The frogs who laid these eggs on leaves and boulders were tiny members of the fanged frog family. The caretakers of the nests were all males. According to Frederick, egg-guarding behavior from male frogs is uncommon, but not unheard of. The team theorizes that the frogs’ unusual reproductive behaviors may also relate back to their smaller fangs. While some of their relatives have larger fangs that help them ward off competition, these frogs likely evolved a way to lay their eggs away from the water and lost the need for such big fangs. 

“It’s fascinating that on every subsequent expedition to Sulawesi, we’re still discovering new and diverse reproductive modes,” says Frederick. “Our findings also underscore the importance of conserving these very special tropical habitats. Most of the animals that live in places like Sulawesi are quite unique, and habitat destruction is an ever-looming conservation issue for preserving the hyper-diversity of species we find there. Learning about animals like these frogs that are found nowhere else on Earth helps make the case for protecting these valuable ecosystems.”

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While refrigerators store food at safe temperatures and keep it fresh, they can also be a breeding ground for fuzzy gray mold that spoils fruit. Most molds thrive in warm temperatures, but many can grow in the refrigerator by producing spores. The spores can go airborne and accumulate inside the refrigerator and infect fruits and vegetables. However, plants may not be completely defenseless against this creeping fungus. According to a study published December 15 in the journal Cell Host & Microbe, plants use a stealth molecular weapon to attack the cells of gray mold. 

[Related: A bit of care can keep your houseplants from sheltering harmful mold.]

To look closer, the team profiled the messenger RNA (mRNA) molecules present in a plant called Arabidopsis thaliana–or Thale cress–against gray mold (Botrytis cinerea). mRNA are small molecules within the cells that have a set of instructions like a blueprint. While all three types of RNA can build proteins, mRNA is the one that acts like a messenger, delivering the recipe for a protein. 

In the lab, they observed how the plants send small lipid “bubbles” called extracellular vesicles that are filled with RNA and the mRNA molecules that can attack the cells of the aggressive mold. Once the bubbles are inside, the molecules can suppress the infectious mold cells.

“Plants are not just sitting there doing nothing. They are trying to protect themselves from the mold, and now we have a better idea how they’re doing that,” study co-author and University of California, Riverside microbiologist Hailing Jin said in a statement.

Jin’s team previously found that plants use these same bubbles to send small mRNA molecules that can silence the genes that make the mold more poisonous. This new study found that these bubbles have mRNA molecules that attack important cellular processes in the mold cells, including the functions of organelles.

“These mRNAs can encode some proteins that end up in the mitochondria of the mold cells. Those are the powerhouses of any cells because they generate energy,” said Jin. “Once inside, they mess up the structure and function of the fungal mitochondria, which inhibits the growth and virulence of the fungus.”

The team on this study is not entirely sure why the fungus accepts the lipid bubbles to begin with. They believe that the fungus may simply be hungry. Fungi may take in the bubbles for the nutrients, unaware that there is something dangerous inside. For the plants, this is an efficient strategy because one tiny mRNA molecule can have a large effect on the fungus. According to Jin, molecular weapons with mRNA can be translated into millions of copies or proteins and amplify their effect. 

Interestingly, mold uses these same lipid bubbles to deliver small, damaging RNAs into the plants that they infect. They will suppress the plant’s immunity and provide good protection for the genetic information the fungi needs to take over the plant host. 

[Related: Nightmare-fuel fungi exist in real life.]

“During infections, there are always a lot of communications and molecule exchanges where plants and fungi try to fight against each other,” Jin said. “Previously people looked at proteins being exchanged. Now, modern technology has enabled us to discover another important group of players in this battle.”

In future studies, the team hopes to use the discovery of this stealth RNA delivery system to create more eco-friendly fungicides. They believe that these potential RNA-based fungicides wouldn’t leave toxic residue in the environment or affect animals and humans. 

“There is a never-ending battle to control pests and pathogens,” said Jin. “If we can deliver mRNA that interferes with mold cellular functions, we may be able to help plants more effectively fight in this battle.”

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Aardvarks (Orycteropus afer) are a crucial part of the ecosystem in sub-Saharan Africa. They eat termites that can destroy human-built structures and are ecosystem engineers like beavers. They build large tunnels underground and these burrows can provide shelter that protects other animals. Their poop can also offer clues to how this elusive species is impacted by climate change. 

[Related: Humans are now the African savannah’s top predator.]

In a study published December 13 in the journal Diversity and Distribution months of poop samples revealed that the aridification–or drying and heating–of the aadvarks’ landscape is isolating the animals from one another. The study’s authors believe this could have implications for the species’ long-term survival.

“Everyone had heard of aardvarks and they are considered very ecologically important but there has been little study of them,” study co-author and Oregon State University wildlife biologist Clint Epps said in a statement. “We wanted to see if we could collect enough data to begin to understand them.”

Aardvarks are burrowing nocturnal mammals that can weigh up to 180 pounds. They have long snouts that they used to dig out ant and termite hills. They are primarily found throughout the southern two-thirds of Africa. Aardvarks are often compared to pigs and the South American anteater, but they are not related to them. Their closest living relatives are golden moles, manatees, and elephants. 

They are categorized as a species of least concern by the IUCN Red List, partially due to the broad range of ecosystems that they can live in. However, little is known about their current population trends or their real distribution across the landscape since they are difficult to study. 

“During times of rapid environmental change, evaluating and describing changes in the landscape where a species lives is important for informed conservation and management decisions,” study co-author and Oregon State University wildlife geneticist Rachel Crowhurst said in a statement. 

Aardvark DNA has been examined in the past for studies on how mammals evolved, but never using wild aardvark populations. Eps and Crowhurt believe that aardvarks are understudied because they are nocturnal, difficult to trap, and live in low densities across large and often remote landscapes. 

They also bury their poop. Epps learned how to recognize aardvark tracks and how to find their buried fecal matter while working as post-doctoral researcher nearly two decades ago in Tanzania. He returned to Africa for six weeks in 2016 to see if he could still spot the signs of aardvark digging and track them through the bush to find the buried treasure.  

“I wanted to work on a system that was understudied, where anything I learned would likely be truly new information to the scientific community,” Epps said. “I also wanted to work over large landscapes, on foot, alone or with a friend or with guards when needed, in protected areas, with minimal logistical support and little cost.”

In this new study, the team used the genetic information aardvark poop samples as a way to better understand the range of where they live. They surveyed eight protected and four privately owned areas in South Africa, two protected areas in Eswatini, and one location in Kenya. In total, they collected 253 fecal samples and analyzed 104 high quality samples for their genetic information.

Next, they used the genetic information to make inferences about where the aardvarks were distributed and how they moved across the landscape. For instance, if the genetic testing revealed that fecal samples collected in different spots all came from the same aardvark, the team used that to determine the scale of an individual animal’s movement.

The genetic information suggested that there are three regional divisions of aardvarks in South Africa. The animals in the western, central, and eastern regions of the country were also somewhat isolated. Individuals were detected at various locations separated by up to 4.3 miles. Their home ranges may be larger than previously determined, particularly in more arid areas where food may be more scarce. 

[Related: Rare parasites found in 200 million-year-old reptile poop.]

Closely related aardvarks were detected as far as 27.3 miles apart and individuals found less than 34 miles were more genetically similar. The team also found that aardvarks may disperse up to 34 miles from where they are born. The genetic differences between individuals was larger when the landscapes between the animals were more dry and hot, which suggests that the movement throughout those arid areas may be restricted.

“Our initial findings suggest that climate change will increase habitat fragmentation and limit gene flow for aardvarks, particularly where precipitation is expected to decrease and temperature increase,” Epps said. “With aridity expected to increase in southernmost Africa under most climate change scenarios, the need for further research is clear.”

The team plans to perform genomic analysis on new samples and conduct field work across a wider area.

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To survive the dark and snowy Arctic winters, reindeer have evolved unique visual systems. Their eyes change color to adjust to the huge swings in sunlight between Arctic summer and winter, but may do even more to help them forage. A study published December 15 in the journal i-Perception found that their eyes may have evolved to see light in the ultraviolet spectrum to help them find their favorite food in their desolate  home.

[Related: Jackrabbit’s color-changing fur may prepare them for climate change.]

Reindeer primarily eat Cladonia rangiferina (C. rangiferina), which is appropriately nicknamed reindeer moss. This plant is not a moss, but a species of algae-fungus called lichen. It forms a thick and crunchy blanket on the ground across the Earth’s northern latitudes and helps play an important role in the ecosystem as a food source. 

In the study, the team worked in the Cairngorms mountains in the Scottish Highlands, home to Britain’s only reindeer herd. Reindeer were locally hunted to extinction, but began to be reintroduced from Scandinavia in 1952. The Cairngorms are home to more than 1,500 species of lichen, but the reindeer here only rely on C. rangiferina during the winter months

“A peculiar trait of reindeer is their reliance on this one type of lichen,”  study co-author and Dartmouth College anthropologist and evolutionary biologist Nathaniel Dominy said in a statement. “It’s unusual for any animal to subsist so heavily on lichens, let alone such a large mammal.”

When up against snow, the white lichen is invisible to the human eye.. However, co-authors Catherine Hobaiter and Julie Harris from the University of St. Andrews found that C. rangiferina and some other lichen species that supplement the reindeer diet absorb ultraviolet (UV) light. The team used spectral data from the lichen and light filters that were made to mimic reindeer vision and found that the plants may look like dark patches against a bright landscape to the reindeer. They stand out like Dalmatian spots and are easier for the reindeer to locate.

According to Dominy, this is one of the first studies to use a visual approximation of how these mammals may see their world. 

“If you can put yourself in their hooves looking at this white landscape, you would want a direct route to your food,” Dominy said. “Reindeer don’t want to waste energy wandering around searching for food in a cold, barren environment. If they can see lichens from a distance, that gives them a big advantage, letting them conserve precious calories at a time when food is scarce.”

Some animals that can see on the UV spectrum include dogs, cats, pigs, and even ferrets. They generally do this with the short blue photoreceptors called cones present in their eyes. 

Earlier studies have shown that reindeer eyes change from golden in the summer and a vivid blue in the winter. The light-enhancing membrane that gives many animals a shiny eye called the tapetum transitions every season. The blue hue of their eyes is believed to amplify the low levels of sunlight present during polar winters. 

[Related: How do animals see the world?]

“If the color of the light in the environment is primarily blue, then it makes sense for the eye to enhance the color blue to make sure a reindeer’s photoreceptors are maximizing those wavelengths,” Dominy says.

However, the blue tapetum also lets up to 60 percent of UV light pass through to the eye’s color sensors. The reindeer likely see the winter world as a shade of purple the way a human may see a room with a black light. Snow and other UV-reflecting surfaces then shine brightly while surfaces that absorb UV light are dark.

Scientists have investigated why an Arctic animal that is active during the day would have eyes that are so receptive to UV light that reflects off of the snow. This study suggests that the answer to this question is tied to C. rangiferina and other lichens, since UV light doesn’t reflect from those organisms. The team believes that it is possible that reindeer eyes are optimized to single out lichens during the times of year where it is most difficult to find since it is a food staple. 

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About 72 million years ago, a mosasaur the size of a modern great white shark terrorized the Pacific Ocean. Nicknamed Wakayama Soryu or “blue dragon,” the large extinct marine reptile was propelled by extra-long rear flippers and a long finned tail. Wakayama Soryu also had a unique dorsal fin like a shark or dolphin. This back fin would have helped it turn very quickly and precisely in the water, making Wakayama Soryu a formidable foe. This newly described reptile is detailed in a study published on December 11 in the Journal of Systematic Palaeontology.

[Related: Newfound mosasaur was like a giant Komodo dragon with flippers.]

Mosasaurs were marine apex predators that lived when Tyrannosaurus rex and other late Cretaceous dinosaurs dominated life on land. They ate cephalopods, fish, sharks, birds, and were even known to munch on other mosasaurs. Mosasaurs died off during the same mass extinction event that killed almost all of the dinosaurs about 66 million years ago. Mosasaur specimens have been uncovered all over the world, including in North Dakota, The Netherlands, and Morocco. 

Wakayama Soryu was found along the Aridagawa River in Wakayama Prefecture along the central coast of Japan. Its dragon nickname is a reference to Japanese folklore. 

“In China, dragons make thunder and live in the sky. They became aquatic in Japanese mythology,” study co-author and University of Cincinnati vertebrate paleontologist Takuya Konishi said in a statement. 

The specimen was first discovered in 2006 along by study co-author Akihiro Misaki from the Kitakyushu Museum of Natural History & Human History. Misaki was searching for ammonite fossils when he spotted an interesting dark fossil in the sandstone. A closer look at the dark stone revealed that it was a back bone and part of  the most mosasaur skeleton ever found in Japan of the northwestern Pacific.

“In this case, it was nearly the entire specimen, which was astounding,” Konishi said.

Konishi has spent decades studying ancient marine reptiles, but this new specimen had some features that defied simple classification. The rear flippers are longer than the front flippers and are even longer than its head. 

“I thought I knew them quite well by now,” Konishi said. “Immediately it was something I had never seen before.”

The Wakayama Soryu has some features that are similar to mosasaurs found in New Zealand and is fairly comparable to a mosasaur specimen found in California. Konishi said it also had nearly binocular vision that would have made it a deadly hunter.

The team categorized the new specimen in the subfamily Mosasaurinae and gave it the scientific name Megapterygius wakayamaensis, to recognize where it was discovered. Megapterygius means “large winged” in keeping with the mosasaur’s enormous flippers. The paddle-shaped flippers were potentially used for locomotion. Another prehistoric marine reptile called the plesiosaur used paddle fins for propulsion, but it was not equipped with a rudder-like tail the way Wakayama Soryu does.

[Related: Megalodon’s warm-blooded relatives are still circling the oceans today.]

“We lack any modern analog that has this kind of body morphology—from fish to penguins to sea turtles,” Konishi said. “None has four large flippers they use in conjunction with a tail fin.”

The team believes that these large front fins might have helped with rapid moving, while the rear fins would have given pitch to dive down or surface. Like other mosasaurus, the tail would have generated powerful and fast acceleration during hunting. 

“It’s a question just how all five of these hydrodynamic surfaces were used. Which were for steering? Which for propulsion?” said Konishi. “It opens a whole can of worms that challenges our understanding of how mosasaurs swim.”

The orientation of the neural spines along the Wakayama Soryu’s vertebrae indicate that it had a dorsal fin, unlike other mosasaurs. The neural spines are arranged in a way that is similar to present-day harbor porpoises, which also have a prominent dorsal fin.

“It’s still hypothetical and speculative to some extent, but that distinct change in neural spine orientation behind a presumed center of gravity is consistent with today’s toothed whales that have dorsal fins, like dolphins and porpoises,” Konishi said.

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Adjusting to life in cold air temperatures has been key to survival for the Arctic’s seals. Those adaptations go beyond thick layers of blubber for insulation and up into the pinniped’s nose. A study published December 14 in the Biophysical Journal found that Arctic seals have more convoluted nasal passages than seals that live in more mild places. 

[Related: Hungry seals may have begun following their whiskers 23 million years ago.]

Warming the air

In cold and dry places, animals lose moisture and heat when they breathe. Warmer and wet air is important for lung function, so breathing in cold air can put the lungs in danger and may make humans more susceptible to respiratory viruses. To help minimize the risk, most birds and mammal species have complex bones called maxilloturbinates inside their nasal cavities. These porous, bony shelves are covered with mucus and tissues that warm and humidify inhaled air. Maxilloturbinates also reduce the amount of heat and moisture that is lost when an organism breathes out.

Researchers believe that the nose structure helps Arctic seals efficiently retain moisture and heat as they inhale and exhale. 

“Thanks to this elaborate structure in their nasal cavities, Arctic seals lose less heat through nasal heat exchange than subtropical seals when both are exposed to the same conditions,” Signe Kjelstrup, a study co-author and physical chemist at the Norwegian University of Science and Technology, said in a statement. “This provides an evolutionary advantage, especially in the Arctic where heat loss is energy dissipation, which must be replenished by food.”

According to Kjelstrup, Arctic seals retain 94 percent of the moisture in the air when they breathe in and out. Most of the water added to the air when they inhale is then recovered when they exhale.  

‘You can’t find reindeer in the middle of the Mediterranean’

The structure of maxilloturbinates varies between species. Reindeer noses also enable efficient heat exchange, but since they are only found in colder climates, Kjelstrup’s team turned to seals.

“You can’t find reindeer in the middle of the Mediterranean, but seals live in many different environments, so they allowed us to test this question,” said Kjelstrup. “And we knew from a previous study that Arctic seal noses are sponge-like and very dense, whereas the Mediterranean seal nose has a more open structure.”

In the study, the team used computer tomography to create 3D models of the nasal cavities of two seal species–the Arctic bearded seal (Erignathus barbatus) and the Mediterranean monk seal (Monachus monachus). Next, they used energy dissipation models to compare how well each species warmed and moistened air when they inhaled and reduced the amount of heat and moisture lost when they exhaled.

[Related: Baby seals sing bass notes when they want attention.]

They tested the models of both species’ noses under Arctic conditions of -22°F and at about 50°F, or a cold day for a Mediterranean monk seal. They also adjusted different parameters within the model to highlight the crucial geometrical features of the nasal cavity.

According to the model, Arctic bearded seals are more efficient at retaining heat and water exchange in both Arctic and subtropical temperatures. At -22°F, the Mediterranean monk seals lost 1.45 times as much heat and 3.5 times as much water per breath cycle than the bearded seals lost. At 50°F, the Mediterranean monk seals lost 1.5 times as much heat and 1.7 times as much water.

It appears that the Arctic seal’s more complex and dense nasal cavity provided this advantage. Specifically, the team found that the increased perimeter of the Arctic seal’s maxilloturbinates is the key to limiting energy dissipation at lower ambient temperatures. 

While the study looked at the amount of heat loss for one inhalation and exhalation, the role breathing rate plays remains unclear. These breathing cycles are particularly complicated for seals, who will pause their breathing for several minutes at a time when they dive under water and ice.

Energy efficient pinnipeds

The team hopes to look deeper into the nasal structures of other species to see if different parts provide evolutionary advantages in other climates. 

“The camel, for instance, doesn’t need to save much on heat, but it does need to save on water, so one may speculate that it could tell us something about relative importance of the two,” said Kjelstrup.

They also plan to look to animals for cues on how to build more efficient heat exchange and ventilation systems. 

“If nature manages to create such great heat exchangers, I think we should copy that in engineering to create more efficient processes, for instance, in air conditioners,” said Kjelstrup.  

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If you naturally wake up earlier in the morning, some very old genetic variants may be behind your sleep patterns. Humans’ internal circadian clocks might be partially influenced by genetic material left behind by extinct Neanderthals. The findings are described in a study published December 14 in Genome Biology and Evolution and provides a window into how the sleep cycles of Neanderthals differed from our earliest ancestors. Studies like this one could be a step towards a better understanding of how genetic material from extinct hominins affects modern humans.   

Our bodies respond to the environment

Modern Homo sapiens trace their origins back 300,000 years. Biological features in these early humans were shaped by environmental factors like sunlight or altitude. Roughly 70,000 years ago, the ancestors of modern Eurasian humans began to migrate out of Africa north towards Europe and Asia. Here, they experienced new environments and more seasonal variation in both temperatures and daylight. 

[Related: Night owls can become early birds. Here’s how.]

“We also know from other species that live across broad ranges of latitude that their circadian clocks often adapt to the differences in light/dark cycles,” study co-author and University of California, San Francisco computational biologist Tony (John) Capra tells PopSci. “In particular, in higher latitudes there is more seasonal variation in light/dark cycles over the course of the year than in more equatorial latitudes.”

They also encountered different types of early hominins as they left Africa, including Denisovans and Neanderthals. The different environmental conditions on these northern continents meant that Neanderthals and Denisovans had different genetic variations from those coming out of Africa. When they began to interbreed with Neanderthals about 50,000 years ago, it created the potential for humans to get some of the genetic variants that were already adapted to this environment.

Which genes stay and which genes go

Roughly two percent of the present-day Eurasian genome is derived from Neanderthal genetic variants, but which two percent varies. Neanderthal genes have been shown to influence nose shape and even pain sensitivity. Natural selection can remove this older genetic ancestry that is not deemed beneficial to humans as we evolve. However, some of the older hominin genetic variants that remain in today’s human genome have evidence of adaptation. For example, Tibetans living at higher altitudes have variants associated with immune resistance to new pathogens, levels of skin pigmentation, fat composition, and differences in hemoglobin levels.

In the new study, Capra and co-authors were curious if the Neanderthals who lived at higher latitudes may have genetic variants that adapted to changes in environment over hundreds of thousands of years. They also wondered if the interbreeding influenced variation in the circadian rhythm that can make someone an early riser. 

[Related: Sex, not violence, could’ve sealed the fate of the Neanderthals.]

The researchers identified about 200 genes that are related to how light and temperature affects our circadian clock and about 20 that are crucial to our internal clocks themselves. “It turns out that the genes themselves are very similar, but what really matters is how much and when they are made,” says Capra. 

After pinpointing these genes, the team explored if the variants that moved from Neanderthals into modern humans have any associations with the body’s preferences for wakefulness and sleep. They looked at genetic data from the UK Biobank and found that many of the Neanderthal variants in modern humans affect sleep preference. In particular, the tendency to wake up early–or morningness–stuck out. Increased morningness is associated with a shortened circadian clock that is likely beneficial for those living at higher latitudes. Morningness has been shown to enable a faster alignment of the external cues that it’s time to fall asleep or wake up, like changes in sunlight. 

“We used machine learning methods to predict from Neanderthal DNA sequences how the ways that they turned the circadian genes on and off differed from in modern humans,” says Capra. “In general, it seems that having a faster running clock leads people (and other organisms) to be earlier risers and have an easier time adapting to seasonal variation.”

This increased morningness may have been evolutionarily beneficial for our ancestors living in higher latitudes, so the genetic variants associated with it would have been worth keeping. 

Sentinel hypothesis

Exploring the genetics behind what makes some of us early birds and others night owls is part of an emerging–yet difficult to prove–evolutionary theory called sentinel hypothesis. There could be an evolutionary benefit to having a mixture of sleep and wake patterns and in a given human population. To increase chances of survival, animals living in groups should trade off keeping watch, with some sleeping while others are awake. Study co-author and Vanderbilt University computational biologist Keila S. Velazquez-Arcelay identified a few genetic variants that could provide evidence for this.

“Keila discovered a few genetic variants that are associated with chronotype that have evidence of long-term ‘balancing’ selection. In other words, evolution appears to have preferred to maintain variation at these sites,” says Capra. 

In future work, the team from this study is interested in testing the effects of these Neanderthal genetic variants on circadian clocks in cells. According to Capra, using cells allows them to quickly introduce the Neanderthal variants and evaluate their effects. They are also curious to find patterns across different populations and see if this analysis technique can be applied to genes involved in immune system function, thermoregulation, and metabolism.

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A zoologist from the University of Otago in New Zealand spotted a rare bird with distinct half-male and half-female plumage. Hamish Spencer and amateur ornithologist John Murillo took photos and video of a wild green honeycreeper (Chlorophanes spiza) while on vacation in Colombia. A report on the find was published in the Journal of Field Ornithology and represents the second recorded example of gynandromorphism in this species in more than a century. 

[Related: These female hummingbirds don flashy male feathers to avoid unwanted harassment.]

A bilateral gynandromorph is an animal that is born with one male half and one female half. The animal is usually divided down the middle with characteristics of two sexes in one body. Bilateral gynandromorphism has been documented in other animals including bees, butterflies, spiders, and stick insects. Cardinals and the rose-breasted grosbeak have also been documented with this division, but bilateral gynandromorphs are believed to be rare.

“Many birdwatchers could go their whole lives and not see a bilateral gynandromorph in any species of bird. The phenomenon is extremely rare in birds, I know of no examples from New Zealand ever,” Spencer said in a statement. “It is very striking, I was very privileged to see it.”

Studying gynandromorphs are important for our understanding of how biological sex is determined in birds and their sexual behavior. Male green honeycreepers have predominantly blue plumage. Female green honeycreepers have green plumage. The observed bird has both. 

“This particular example of bilateral gynandromorphy–male one side and female the other–shows that, as in several other species, either side of the bird can be male or female,” said Spencer. 

While there are a range of theories of how gynandromorphic animals form, scientists believe that it could occur in birds when a female egg cell develops with two nuclei. For mammals, male sex cells generally have one copy of each sex chromosome (X and Y) and females have two copies of the X chromosome. In birds, it’s the opposite and their sex chromosomes are designated as Z and W instead of X and Y. The female’s egg cells will have a single copy of each (ZW) chromosome in their nucleus, while the male’s sperm will have two Z’s. According to ornithologist Daniel Hooper, gynandromorphism likely occurs if a female egg cell develops with two nuclei—one with a Z and one with a W. It is then “double fertilized” by the two Z-carrying sperm, resulting in a gynandromorph.

[Related: Sex and gender binaries don’t tell the entire story of life.]

The team did not observe any courtship behavior or take any blood or tissue samples to study its chromosomes. It was also not clear if the bird was fertile or reproduced over the 21 months that the bird was reportedly present in the forest in Villamaría, Colombia. The bird tended to keep to itself and acted as the other members of its species. 

There are five species of honeycreepers. Green honeycreepers live in southern Mexico, south towards Brazil, Colombia, and Trinidad. Green honeycreepers are generally found on the edges of evergreen forests, gardens, and plantations in Central and South America. They are only five to five and a half inches long and weigh less than a pound. Green honeycreepers eat fruit and some arthropods and some nectar from plants. Scientists also believe that they are doing well and are categorized as Least Concern on the IUCN Red List.

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Your biological center for thought, comprehension, and learning bears some striking similarities to a data center housing rows upon rows of highly advanced processing units. But unlike those neural network data centers, the human brain runs an electrical energy budget. On average, the organ functions on roughly 12 watts of power, compared with a desktop computer’s 175 watts. For today’s advanced artificial intelligence systems, that wattage figure can easily increase into the millions.

[Related: Meet ‘anthrobots,’ tiny bio-machines built from human tracheal cells.]

Knowing this, researchers believe the development of cyborg “biocomputers” could eventually usher in a new era of high-powered intelligent systems for a comparative fraction of the energy costs. And they’re already making some huge strides towards engineering such a future.

As detailed in a new study published in Nature Electronics, a team at Indiana University has successfully grown their own nanoscale “brain organoid” in a Petri dish using human stem cells. After connecting the organoid to a silicon chip, the new biocomputer (dubbed “Brainoware”) was quickly trained to accurately recognize speech patterns, as well as perform certain complex math predictions.

As New Atlas explains, researchers treated their Brainoware as what’s known as an “adaptive living reservoir” capable of responding to electrical inputs in a “nonlinear fashion,” while also ensuring it possessed at least some memory. Simply put, the lab-grown brain cells within the silicon-organic chip function as an information transmitter capable of both receiving and transmitting electrical signals. While these feats in no way imply any kind of awareness or consciousness on Brainoware’s part, they do provide enough computational power for some interesting results.

To test out Brainoware’s capabilities, the team converted 240 audio clips of adult male Japanese speakers into electrical signals, and then sent them to the organoid chip. Within two days, the neural network system partially powered by Brainoware could accurately differentiate between the 8 speakers 78 percent of the time using just a single vowel sound.

[Related: What Pong-playing brain cells can teach us about better medicine and AI.]

Next, researchers experimented with their creation’s mathematical knowledge. After a relatively short training time, Brainoware could predict a Hénon map. While one of the most studied examples of dynamical systems exhibiting chaotic behavior, Hénon maps are a lot more complicated than simple arithmetic, to say the least.

In the end, Brainoware’s designers believe such human brain organoid chips can underpin neural network technology, and possibly do so faster, cheaper, and less energy intensive than existing options. There are still a number of hurdles—both logistical and ethical—to clear, but although general biocomputing systems may be years down the line, researchers think such advances are “likely to generate foundational insights into the mechanisms of learning, neural development and the cognitive implications of neurodegenerative diseases.”

But for now, let’s see how Brainoware can do in a game of Pong.

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The stomach of the teenage tyrannosaur Gorgosaurus libratus is a gift that keeps on giving. A team of paleontologists in Canada found the remains of two meals preserved inside of its stomach cavity, including the partially digested drumsticks of two birdlike dinosaurs. The findings were described in a study published December 8 in the journal Science Advances and is the first known time that well-preserved gut continents have been discovered in a fossilized tyrannosaur.

[Related: The ghosts of the dinosaurs we may never discover.]

Gorgosaurus lived about 75 million years ago, or several million years before its more famous relative the Tyrannosaurus rex. In the study, the Gorgosaurus was estimated to be between five and seven years old when it died, or a teenager in dinosaur years. It probably weighed about 738 pounds, or 13 percent of the body mass of a fully grown Gorgosaurus. Adults were about 33 feet long and weighed upwards of 2,200 pounds. 

The fossil was first discovered in 2009 by staff from the Royal Tyrrell Museum of Palaeontology in Dinosaur Provincial Park in Alberta. Technicians noticed strange features poking out of the fossil’s rib cage while they were preparing it. These turned out to be small toe bones. Gut contents like these are rarely preserved in dinosaur fossils, but this specimen had the dismembered remains of two herbivorous dinosaurs–Citipes elegans. 

The tyrannosaur only ate the hind limbs of each tiny Citipes and they appear to be the last and second-to-last meal that the Gorgosaurus consumed before it died. 

“It must have killed… both of these Citipes at different times and then ripped off the hind legs and ate those and left the rest of the carcasses,” study co-author and University of Calgary paleontologist Darla Zelenitsky told CNN. “Obviously this teenager had an appetite for drumsticks.”

Tyrannosaurs digested the bones of their prey in their stomach, instead of regurgitating them the way present-day birds do. Since the elements of the two Citipes individuals are at different stages of digestion, the team concludes that these were two different meals eaten hours or days apart. 

This specimen also shows direct evidence that young Gorgosaurus had different diets than adults. Fully grown Gorgosaurus are known to have hunted megaherbivore dinosaurs including ceratopsians (horned dinosaurs) and hadrosaurs (duck-billed dinosaurs), based on the tooth marks left behind on bones. They used their massive skulls and teeth to capture their large prey, chomp through bone, and then scrape and tear the flesh. 

[Related: Scaly lips may have hidden the T-rex’s fearsome teeth.]

Juveniles were not yet built to hunt such large prey. They had more narrow skulls, blade-like teeth, and long and slender hind limbs. This made them better suited for capturing and dismembering small and young prey like the Citipes found in this specimen. The team also believes that this kind of prey was a preferred snack for these teenage dinos.

“This is a great case of showing small tyrannosaurids fed on small dinosaurs, much smaller than themselves,” University of Maryland paleontologist Thomas Holtz told The Washington Post., “Whereas the grown-up versions, we have the evidence of their bite marks on big adults that were about the same size as adults.”

The dietary shift towards eating bigger prey likely began around the age of 11. This is when the tyrannosaurs’ skulls and teeth started to get more robust. Differences in diet provide a competitive advantage by lessening competition for resources in modern ecosystems. This same strategy could have been applied when tyrannosaurs like Gorgosaurus lived. It would have allowed juveniles and adults to coexist in the same ecosystem with less conflict. Occupying different ecological niches during their lifespan was likely one of the keys to tyrannosaurs’ evolutionary success as some of Earth’s carnivores. 

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Researchers at Drexel University are experimenting with imbuing concrete with living organisms to extend the building material’s lifespan. And although the new approach is based on cutting-edge technology, the underlying engineering strategy originates within the human body.

Concrete is second only to water as the most consumed material on Earth—a particularly problematic statistic, given the enormous carbon emissions of its manufacturing process. A number of promising, green updates to the millennia-old structural material are already in the works, but another avenue to reduce concrete’s environmental impact is to extend its longevity. Depending on the surrounding environment, concrete can begin to weaken and break down barely 50 years after setting. Delaying this degradation using innate real-time repair mechanisms could offer a solid way to get more out of the material.

[Related: Dirty diapers could be recycled into cheap, sturdy concrete.]

As detailed in a new paper recently published in Construction and Building Materials, a team of engineering researchers at Drexel University have developed a new polymer “BioFiber” coated in bacteria-infused hydrogel, all within a damage-responsive casing half a millimeter thick. The BioFiber is then arranged in layers of grid patterns as concrete is poured, serving as a reinforcing additive much in the way builders have used straw or horsehair to strengthen bricks for millennia. Of course, these reinforcements can only do so much—but when the team’s BioFibers begin to falter is when they really shine.

“In our skin, our tissue [repairs] naturally through multilayer fibrous structure infused with our self-healing fluid—blood,” Amir Farnam, an associate professor in Drexel’s College of Engineering and research co-lead, said in a December 8 university profile. “These BioFibers mimic this concept and use stone-making bacteria to create damage-responsive, living, self-healing concrete.”

Inside each BioFiber is a cache of Lysinibacillus sphaericus in their dormant, endospore form. Generally found in soil, the bacteria undergoes a process known as microbial induced calcium carbonate precipitation—basically, it generates a rock-like substance as it consumes its nutrients.

This could be particularly handy if the bacteria could be found near, say, a newly formed crack within a certain, popular building material. After the team’s BioFibers break under stress, water from the outside environment eventually finds its way into the concrete, where it comes into contact with the endoscopic bacteria. This then activates Lysinibacillus sphaericus, which begins to push out and up towards the surface—all while beginning its microbial-induced calcium carbonate precipitation. That calcium carbonate then fills the cracks in question, where it hardens into ostensibly a cement scab, much when dried blood covers and protects a cut. In recent tests, the concrete “healed” itself within two days.

Although researchers still need to better understand and control the BioFiber-imbued material’s repair time, self-healing materials may one day help reduce the need for additional, climate-costly concrete.

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After spending millions of years tucked away in rocks, fossils can sometimes resemble a completely different living thing. A turtle fossil might even bear a striking resemblance to a plant. When a team of paleontologists and paleobotanists re-examined a plant fossil first described about 20 years ago, they found out that it is actually the fossil of a baby turtle. The re-discovery is described in a study published December 7 in the journal Palaeontologia Electronica.

[Related: This 6-million-year-old turtle shell still has some DNA.]

Colombian priest Padre Gustavo Huertas collected rocks and fossils near the town of Villa de Levya from the 1950s to the 1970s. Two of the specimens Padre Huertas found were small, round rocks that had lines on them that looked like leaves, so he classified them as a type of fossil plant. They were described by Huertas in 2003 as Sphenophyllum colombianum and they date back to when dinosaurs roamed the Earth between 132 and 113 million years (Early Cretaceous period). 

This fossil’s age and where it was found piqued the interest of Fabiany Herrera, the assistant curator of fossil plants at the Field Museum in Chicago and a paleobotanist at the Universidad Nacional de Colombia in Bogotá, Colombia and his postdoctoral student Héctor Palma-Castro.

“I am neither a turtle expert nor a paleo vertebrate [expert], but my student Héctor and I knew this specimen was not a fossil leaf,” Herrera tells PopSci. “Fossil leaves are usually preserved pretty flat and don’t have a bone-like texture, so we were quite intrigued as soon as we saw the fossil for the first time.” 

At first glance, the fossils that are about two inches in diameter, looked like rounded nodules with the preserved leaves of the plant Sphenophyllum. They then noticed some key features weren’t quite right. They searched through the university’s fossil collections for other plants for comparison, and deciphering the shape and margin of the leaf in question was a challenge. The lines seen in the fossil did not look like the veins of a plant, and Herrera and Palma-Castro thought it could be bone. 

For help, Herrara reached out to Edwin-Alberto Cadena, a colleague and paleontologist who specializes in turtles and other vertebrates at the Universidad del Rosario in Bogotá. Cadena examined photos of the fossil and believed it looked like the upper shell of a turtle called the carapace. He realized that not only was it a turtle, but a hatchling of one of the world’s oldest extinct turtle species that could grow up to 15 feet long.

“Considering that the fossil hatchlings were found in the same rocks where one of the most complete and oldest marine turtles from the Early Cretaceous has been discovered, known as Desmatochelys padillai, we believe that these hatchlings could correspond to this extinct species,” Cadena tells PopSci. “Desmatochelys padillai belongs to a group of marine turtles known as protostegids, which inhabited the planet during the Cretaceous period and includes some of the largest turtles ever to have lived on Earth.”

[Related: Gigantic fossils hint at super-sized 7,000-pound sea turtle.]

Cadena and his student, Diego Cómbita-Romero of the Universidad Nacional de Colombia, further examined the specimens and compared them with fossilized turtle shells and modern shells.

 “When we saw the specimen for the first time I was astonished, because the fossil was missing the typical marks on the outside of a turtle’s shell,” Cómbita-Romero said in a statement. “It was a little bit concave, like a bowl. At that moment we realized that the visible part of the fossil was the other side of the carapace, we were looking at the part of the shell that is inside the turtle.”

To determine its age, they looked at the thickness of its carapace and the spots where the animal’s ribs were joined together in solid bone. The turtle was likely between 0 and 1 year old at death and in a post-hatchling stage with a slightly developed carapace when it died. Cadena says it is very rare to find hatchlings of fossil turtles since the bones in their shells are quite thin and can easily be destroyed over time. 

The team does not fault Padre Huertas for the mistake, as the features that he thought were leaves and stems are actually the modified rib bones and vertebrae that make up a turtle’s shell. Cómbita-Romero and Palma-Castro nicknamed the specimens Turtwig after a Pokémon that’s half-turtle and half-plant.

“In the Pokémon universe, you encounter the concept of combining two or more elements, such as animals, machines, plants, etc. So, when you have a fossil initially classified as a plant that turns out to be a baby turtle, a few Pokémon immediately come to mind. In this case, Turtwig, a baby turtle with a leaf attached to its head,” paleobotany postdoctoral student Palma-Castro said in a statement. “In paleontology, your imagination and capacity to be amazed are always put to the test. Discoveries like these are truly special because they not only expand our knowledge about the past but also open a window to the diverse possibilities of what we can uncover.”

The team hopes to conduct more examinations of these specimens, including using  micro-computer tomography to peer into the more delicate details of the bone and anatomy. They also plan to search for new fossils preserved inside these same spherical rocks and hopefully will find better-preserved hatchlings and even fully intact skeletons.

“The general public is crucial for discovering new fossils and meteorites in the US and Latin America,” says Herrera. “At the Field Museum, we receive lots of inquiries every year. Next time you find an interesting specimen and don’t know what it is, ask an expert! You could discover an exciting new species or rock from our planet’s history.”

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Four-legged robots like Boston Dynamics’ Spot and Cheetah owe almost all their agility to fancy footwork. While they may visually move much like their mammalian counterparts, the anatomical inspirations largely stop at their legs. In biology, however, a quadrupedal animal’s movement, flexibility, and intricate motor functions stem almost entirely from its spine. Replicating that complex system of stacked vertebrae in robots is much more difficult than the legs—but if artificial spines could be integrated into such designs, engineers could open up entirely new avenues of precise maneuverability.

[Related: A new tail accessory propels this robot dog across streams.]

Now, engineers are reportedly a few steps further towards spine-centric quadruped bots thanks to a research team’s very uncanny, rodent-inspired robot. Writing in Science Robotics on Wednesday, collaborators across Germany and China have unveiled NeRmo, a biomimetic, four-legged robot that relies on a novel motor-tendon framework to scurry its way around environments.

As far as looks go, NeRmo mirrors a mouse’s skeletal system—although the ears, although cute, are likely superfluous. The robot’s rigid front half houses its electronics systems, while its latter half functions much as an actual flexible spine would, with four lumbar and lateral joints. Artificial tendons thread through the spine as well as the robot’s elbow and knee joints allow NeRmo even more mouselike movements alongside quicker turning times. 

According to collaborators at the Technical University of Munich, University of Technology Nuremberg, and China’s Sun Yat-Sen University, NeRmo’s tendon-pulley system precludes the need for any musculature while still allowing for smooth flexion capabilities across the lateral and sagittal planes, i.e. side-to-side, and up-and-down.

To test their new design, the team ran NeRmo through a series of four experiments to demonstrate static balancing, straight-line walking, agile turning, and maze navigation. Each trial included two rounds—one with the spinal system engaged, and another with it disabled. Across the board, NeRmo performed their tasks better, faster, and more accurately when it integrated the spine into its movements.

Maze navigation, however, was NeRmo’s true shining moment. With its spine engaged, the mouse-bot completed its labyrinth runs an average of 30 percent faster than simply waddling through without spinal support.
Although still in its early stages, researchers believe further design tweaking and integration of the spinal systems into future quadruped robots could vastly improve their functionality. If NeRmo wasn’t proof enough, think of it this way—MIT’s Cheetah can gallop at 13 feet-per-second with just one actuated joint mimicking spinal flexion in the sagittal plane. NeRmo, meanwhile, has eight joints.

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Mice may be one of only a small group of mammals that can recognize themselves in a mirror. A group of laboratory mice were given an assessment of consciousness called the mirror test. The study published December 5 in the journal Neuron suggests that some rodents display a behavior that resembles self-recognition and might be able to differentiate themselves from other mice.

[Related: What video game-playing mice taught neuroscientists about memory-making.]

Previous studies have shown that mammals including humans, great apes, chimpanzees, elephants, and dolphins have demonstrated the signs that they can recognize their reflections. The fish cleaner wrasse and the large-brained bird the Eurasian magpie have also demonstrated this ability in other studies. (However, the mirror test has faced criticism for its ability to measure self-awareness and can produce false negatives in human children.)  

In the study, scientists from the University of Texas Southwestern Medical Center in Dallas marked the foreheads of black-furred mice with a spot of white ink, or black ink on white-furred mice. They observed the mice spending more time grooming their heads in front of the mirror—presumably trying to wash away the new ink. 

However, the team cautions that this does not mean that the mice are fully “self-aware.” The only mice that showed this potentially self-recognition-like behavior were those either already accustomed to mirrors, mice that socialized with other animals who looked like them, and the mice with a relatively large spot of ink on their heads.

“The mice required significant external sensory cues to pass the mirror test—we have to put a lot of ink on their heads, and then the tactile stimulus coming from the ink somehow enables the animal to detect the ink on their heads via a mirror reflection,” study co-author and psychiatrist Jun Yokose said in a statement. “Chimps and humans don’t need any of that extra sensory stimulus.”

Next, the team used gene mapping to identify a subset of neurons located in the hippocampus that are involved in developing and storing visual self-image. According to the team, these brain patterns provide a first glimpse of the neural mechanisms behind self-recognition. Pinpointing this activity has been difficult in neurobehavioral research.

“To form episodic memory, for example, of events in our daily life, brains form and store information about where, what, when, and who, and the most important component is self-information or status,” study co-author and neuroscientist Takashi Kitamura said in a statement. “Researchers usually examine how the brain encodes or recognizes others, but the self-information aspect is unclear.”

They saw that the neurons in the mouse’s hippocampus were activated when the mice appeared to recognize their reflections in the mirror. Socialization may play a key role in the mice developing self-recognizing behaviors. The more socially isolated mice did not exhibit any increase in grooming behaviors during the mirror and ink test. 

[Related: How science came to rely on the humble lab rat.]

“A subset of these self-responding neurons was also reactivated when we exposed the mice to other individuals of the same strain,” says Kitamura. “This is consistent with previous human literature that showed that some hippocampal cells fire not only when the person is looking at themselves, but also when they look at familiar people like a parent.”

In future studies, the team plans to try and disentangle the importance of visual and tactile stimuli like the ink to see whether mice can recognize changes in their reflection without it. This could be achieved with technology similar to popular photo filters like the ones used to create fake bunny ears on social media posts. The team also plans to study how other regions in the mouse brain may be involved in self-recognition and see if these areas of the brain share  information.

“Now that we have this mouse model, we can manipulate or monitor neural activity to comprehensively investigate the neural circuit mechanisms behind how self-recognition-like behavior is induced in mice,” says Yokose.

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When bioluminescent ostracods or ‘sea fireflies’ mate, they perform a courtship dance complete with glowing blue mucus. The males sway together in sync while basking in the light of the shiny slime. This mating ritual is detailed for the first time in a study published November 29 in the journal Proceedings of the Royal Society B.

[Related: Surprise! These sea cucumbers glow.]

Ostracods are tiny crustaceans that are about the size of a sesame seed. They are found in a variety of fresh and saltwater environments, from deep ocean depths to shallow seas to rivers, lakes, and estuaries. The dancing, shrimplike species in the study is called the entraining grassbed downer and was observed in the Caribbean Sea near Panama. 

During this dance routine, male EGDs create their distinct patterns of bioluminescence to attract females. They secrete packets of protein from a specialized gland. The females respond by angling themselves to these bright blue luminous displays and swimming towards the males. According to study co-author Nicholai Hensley, a Cornell University evolutionary biologist who specializes in animal behavior, the other males will then join in a synchronous light display and repeat the same pattern in the water during each dance.

The study found that this very coordinated swim also doesn’t happen randomly. The mating dance sequence only occurs after sunset at nautical twilight, when the moon isn’t bright in the night sky. The team found their level of precision and coordination very surprising. 

“This precise timing leads to the unexpected phenomena of huge waves of light that cascade across the grass bed, with hundreds of males displaying at the same time,” Hensley tells PopSci. “Amazingly, this is very similar in appearance to the fireflies most people are familiar with, where some species are also synchronized. But ostracods and fireflies last shared a common ancestor 500 million years ago, when most animal life was evolving beyond looking slightly more than worm-like.”

Ostracods are special because they evolved their bioluminescence and bioluminescent behaviors completely independently from other animals that act like them. “They are also spectacular little animals, whose whole world escapes notice by 98 percent of people unless you know where to look,” says Hensley.

Luckily, some of Hensley’s collaborators knew where to look and had some luck on their side. In 2017, James Morin, a professor emeritus of ecology and evolutionary biology at Cornell and Todd Oakley, a professor at the University of California, Santa Barbara were diving near the Smithsonian Tropical Research Institute’s Bocas del Toro island research station in Panama. When Morin turned on his dive light to test it out, hundreds of ostracods responded with their own light. According to Morin, there are more than 100 species of signaling ostracods in the Caribbean alone.

[Related: These newly discovered bioluminescent sea worms are named after Japanese folklore.]

“What’s really remarkable about EGD is the duration, the brightness and the density,” Morin said in a statement. “It was a remarkable experience. They really jump out at you. I’ve worked with ostracods for years and this species is spectacular.”

With this discovery, Hensley and study-co-author Trevor Rivers from the University of Kansas set up some preliminary experiments to determine just what the animals were responding to when a light flashed on them. They found that the EDGs are very sensitive to both the time and intensity of a light. 

“It’s how they coordinate their own signals with one another,” says Hensley.

The courtship ritual with snotty light likely evolved about 20 million years ago. However, why the males perform these gyrations is still a mystery. The team only knows that these displays are for attraction purposes, and are still figuring out the other functions. It’s possible that the males are competing with one another for attention, which leads to what Hensley calls a “giant free-for-all.” They also may be cooperating to make a brighter display that could attract more females. The team plans on testing how these displays look to females and measuring their behaviors to better understand this mating dance.

“There’s a whole world filled with new questions and unexplored ideas out there if you pay attention to the little details around you,” says Hensley. “Get out there, pay attention, and take chances, make sure to seize the moments of the rare opportunities that come your way. You can’t predict where it will lead, but you can be sure you learn something along the way.”

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Crocodiles are some of the most fierce ambush-predators in the world. There are only 24 crocodilian species around the world and seven are considered Critically Endangered by the international Union for Conservation of Nature and Natural Resources. Now, a team of scientists have mapped the crocodile family tree, including their extinct relatives called Pseudosuchia. The family tree is detailed in a study published December 4 in the journal Nature Ecology & Evolution and offers insight into the role that the environment has historically played on crocodile evolution. 

[Related: Why scientists gave vaccines to farmed crocodiles.]

Ruling reptiles

Crocodiles and birds share an evolutionary heritage with dinosaurs and pterosaurs, despite there being 11,000 living bird species compared to only 24 crocodile species. Crocodiles are the only living members of a mostly extinct clade called archosaurs or “ruling reptiles.” Archosaurs date back to the Early Triassic, about 251 million to 200 million years ago. 

Archosaurs belong to a group called Pseudosuchia, which includes multiple species that are more closely related to crocodiles than they are to birds. Pseudosuchias went extinct at or before the Triassic–Jurassic extinction event about 201.4 million years ago. However, one group called the crocodylomorphs, survived the major extinction and gave rise to the crocodiles. 

“The fossil record is a rich source of valuable information allowing us to look back through time at how and why species originate, and crucially, what drives their extinction,” study co-author and University of York biologist Katie Davis said in a statement. 

In the study, a team of researchers used the fossil record to build a large phylogeny, or evolutionary family tree of a species or group. The phylogeny included crocodiles and their extinct relatives, so the team could map out how many new species were being formed and how many species were going extinct over time. They then combined this family tree with data on past changes in climate. They were particularly interested in changes to temperature and sea levels to see if the emergence and extinction of species could be linked to climate change. 

Climate change and competition

They found that climate change and competition with other species have shaped the diversity of modern-day crocodiles and their extinct relatives. Surprisingly, the phylogeny also revealed that whether species lives in freshwater, in the sea, or on land plays a key role in its survival. 

When global temperatures increased, the number of species of the modern crocodile’s sea-dwelling and land-based relatives also went up. 

[Related: Crocodiles’ ancient ancestors may have walked on two legs.]

The crocodile’s freshwater relatives were not affected by changes in temperatures. Rising sea levels proved to be their greatest risk for extinction. According to the team, these results provide important insights for conservation efforts of crocodiles and other species in the face of human-made climate change. 

“With a million plant and animal species perilously close to extinction, understanding the key factors behind why species disappear has never been more important,” said Davis. “In the case of crocodiles, many species reside in low-lying areas, meaning that rising sea levels associated with global warming may irreversibly alter the habitats on which they depend.”

To look at how competition might have played a role, the team used the Information Theory. They calculated estimates of numbers of species present at any point in time and compared that number against new species and extinctions. These calculations allowed the team to estimate where climate change or species interactions like competition had a direct impact on whether new species were emerging or going extinct. Unsurprisingly, an increase in competition for resources, possibly from sharks, marine reptiles, or dinosaurs, likely caused the extinction of some species. 

“Crocodiles and their extinct relatives offer unique insights into climate change and its impact on biodiversity in the past, present and future,” said Davis. “Our findings advance our understanding of what factors have shaped, and continue to shape, life on Earth.”

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If you’ve ever been bitten by a mosquito, it was a female insect that chomped on your skin. Female mosquitoes are hematophagous, which means that they feast on animal blood. They then use the blood to produce their eggs. Male mosquitoes living today are not hematophagous. Instead, they survive on plant nectar because their piercing mouthparts–the proboscis–aren’t strong enough to pierce skin.

[Related: When insects got wings, evolution really took off.]

However, male mosquitoes may have been blood suckers hundreds of millions of years ago. A team of paleontologists found two male mosquito fossils from the Lower Cretaceous period with intact piercing proboscis and sharp mandibles needed to suck blood. The specimens are described in a study published December 4 in the journal Current Biology and help to narrow a “ghost-lineage gap” for mosquitoes.

Hematophagy is the ability for insects to suck on the blood of other animals. It’s believed to have evolved from a shift to using piercing-sucking mouthparts to extract fluids from plants instead of animals. Fleas that currently suck animal blood possibly arose from earlier species of the insects that primarily fed on plant nectar. The evolution of hematophagy has been more difficult to trace, partially due to gaps in the insect fossil record.

The fossils examined for this study were found preserved in amber in Lebanon and date back about 130 to 125 million years. Amber is a fossilized tree resin and deposits in Lebanon are some of the oldest known amber samples that contain traces of living things including insects. Studying this material can close “ghost-lineage gaps,” or a chain of ancestors that does not usually appear in the fossil record. Coelacanths are a famous example of a ghost-lineage gap. These lobe-finned have a long fossil record from the Devonian to the Cretaceous–or a period of about 300 million years. However, they were not found in sediments younger than the Cretaceous, so scientists assumed that they had been extinct 80 million years. A living coelacanth was caught off the coast of South Africa in 1938 and another population lives in Indonesia. Coelacanths have just not left any fossils over the past 80 million years. 

Amber deposits can also offer scientists clues into how pollinating bugs and flowering plants co-evolved over time. The pollinators include some members of the Culicidae family of arthropods which has over 3,000 species of mosquitoes. 

“Molecular dating suggested that the family Culicidae arose during the Jurassic, but previously the oldest record was mid-Cretaceous,” study co-author and entomologist at the National Museum of Natural History of Paris André Nel said in a statement. “Here we have one from the early Cretaceous, about 30 million years before.”

[Related: How can we control mosquitos? Deactivate their sperm.]

In the new study, the team describes the fossils of two male mosquitoes from the Cretaceous period that have piercing mouthparts. The parts include a very sharp triangular mandible and elongated structure with small, tooth-like denticles. The presence of these parts suggest that male mosquitoes living during the Late Cretaceous could have been strong enough to pierce the skin and feed on animal blood like their modern female descendents. 

The team also reports that the mosquitoes’ preservation in amber stretches the family tree of insects further back into the Cretaceous period. The fossils also suggest that the evolution of blood-sucking behavior was more complicated than they had previously suspected. According to Nel, the team hopes to investigate why being hematophagous was advantageous to Cretaceous male mosquitoes and why it no longer exists in future studies. 

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Now’s the opportunity to help one of Mexico’s iconic ‘water monsters.’ Animal lovers around the world can now virtually adopt an axolotl, an iconic fish-like amphibian. In late November, a group of ecologists from the National Autonomous University in Mexico City officially relaunched their “Adoptaxolotl” fundraising campaign to conserve the critically endangered axolotls.

[Related: Farmers and scientists unite to save the home of an endangered salamander.]

The 2022 Adoptaxolotl campaign raised over $26,300 towards an experimental captive breeding program and efforts. The goal of the revived virtual adoption program is to restore habitat in the ancient Aztec canals in Xochimilco, a southern borough of Mexico City.

A virtual adoption costs $30 for one month, $180 for six months, or $360 for a full year. Donors can select the age, sex, and name of their watery friend. If salamander budgets are tight this year, donors can buy an axolotl a nice meal for $10. A $50 donation will go to repair one of their homes for $50. Starting at $450, donors with deeper pockets can adopt the axolotl’s refuge on the islands in Lake Xochimilco called chinampas.

While the axolotls will remain in their home in Mexico, donors will receive an adoption kit complete with an identification card, infographic, adoption certificate, and thank-you letter.

The Peter Pan of amphibians

Axolotls (Ambystoma mexicanum) are amphibians that, in the wild, are only found in Lake Xochimilco in Mexico City. They weigh only half a pound at their largest and are about a foot long. They primarily eat insect larvae, worms, fish, and small crustaceans. They are known by their feathery external gills on each side of their heads. While adult axolotls do have lungs, they still primarily rely on their signature gills to breathe.

After most amphibians like frogs grow out of their aquatic phase (tadpoles), they begin the rest of their lives living on land. However, these ‘Peter Pan of amphibians’ do not go through metamorphosis. Axolotls keep many of their larval characteristics and spend their adult life in the water. 

According to Jeff Streicher, Senior Curator in Charge of Amphibians and Reptiles from London’s Natural History Museum, axolotls may have evolved this unusual life cycle because of their environment and the resources available.

“Axolotls are part of a group of closely related salamanders that have a range of lifestyles,” said Streicher. “Some can remain in the water if conditions on land are bad or can leave if, for example, the lake they live in starts to dry up.”

The god of fire and lightning

Axolotls are believed to be named after Xolotl, the Aztec god of fire and lightning. This mischievous deity can take on the form of a salamander to keep from being killed. The word ‘atl” is the term for water in the ancient Aztec language Nahuatl. Axolotl is generally translated to mean “water monster.” It can also mean  “water dog” since Xolotl was also associated with dogs. 

[Related: How we can help the most endangered class of animals survive climate change.]

The animals have become a cultural icon in Mexico for their very unique appearance and Deadpool-like ability to regenerate its limbs. Scientists believe that studying their healing power may help create better methods to repair tissue or even treat cancer. 

Why are axolotls endangered?

According to the scientists behind the fundraiser, the population density of Mexican axolotls has plummeted 99.5 percent in less than two years. Almost all 18 Mexican axolotl species are considered critically endangered. Their main threats include water pollution, the deadly chrytid fungus, and threats from non-native rainbow trout in the area. 

The funds raised from the adoption program will go toward building refuges for the axolotl and restoring its habitats. National Autonomous University ecologist Luis Zambrano told The Washington Post that their habitats have been devastated by Mexico City’s urbanization efforts. 

“A species can’t be a species without its habitat,” Zambrano said. “We went from 6,000 to 36 in less than 20 years. We need funds to conduct another census, but the outlook is grim. It’s more than likely that they’re nearly extinct.”

He added that losing the axolotl in the wild “would be incredibly bad for both Mexican culture and the science world.”

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Every 13 or 17 years, the buzzy mating call of billions of cicadas is the soundtrack of the summer in some parts of the United States. Their clicky noises are so loud that they could potentially be detected by the same fiber optic cables that help deliver high-speed internet. A proof-of-concept study published November 30 in the Entomological Society of America’s Journal of Insect Science describes how this technology could help track the these loud and fleeting insects

[Related: The Brood X cicadas are coming, and you should eat them. Here’s how.]

When hung on a utility pole, fiber optic cables can be used as a sensor to detect changes in temperature, vibrations, and very loud noises. This emerging technology is called distributed fiber optic sensing and it was tested in the study. 

“I was surprised and excited to learn how much information about the calls was gathered, despite it being located near a busy section of Middlesex County in New Jersey,” study co-author and entomologist Jessica Ware said in a statement. Ware is the associate curator and chair of the Division of Invertebrate Zoology at the American Museum of Natural History in New York.

Measuring ‘backscatter’

According to the team, distributed fiber optic sensing is based on finding and analyzing the backscatter when an optical pulse is sent through a fiber cable. Backscatter occurs when small imperfections or disturbances in the cable cause a tiny amount of the signal to bounce back to the source. Technicians can time the arrival of the backscattered light to calculate exactly where along the cable the light bounced back. Monitoring how backscatter varies over time creates a signature of the disturbance. In acoustic sensing, this signature can indicate the frequency of the sound and volume in the cable. 

One sensor can also be deployed on a large segment of cable. According to the study, a 31-mile-long cable with a sensor can detect the location of disturbances at a scale as precise as 3.2 feet. The authors report that this is identical to installing 50,000 acoustic sensors in a tested region that not only synchronized, but don’t require an onsite power supply.

However, according to co-author and NEC Labs America photonics researcher Sarper Ozharar, acoustic sensing in fiber optic cables “is limited to only nearby sound sources or very loud events, such as emergency vehicles, car alarms, or cicada emergences.”

Return of Brood X

In 2021, the Brood X population of cicadas emerged from the ground in at least 15 states. Brood X is the largest of several populations of cicadas that emerge on 17-year cycles. Ozharar, Ware, and colleagues from NEC Laboratories America, Inc. took this opportunity to use the lab’s fiber-sensing test apparatus to see if they could pick up the Brood X cicadas buzzing in trees. The cable was cable strung on three 35-foot utility poles in Princeton, New Jersey between June 9 and June 24, 2021.

[Related: The world’s internet traffic flows beneath the oceans—here’s how.]

The cable picked up the insects’ sounds. The buzzing appeared as a strong signal at 1.33 kilohertz (kHz) via the fiber optic sensing. This matched the frequency of the cicadas’ call when it was measured with a traditional audio sensor in the same location. 

The team also saw the cicadas’ peak frequency varying between 1.2 kHz and 1.5 kHz. This pattern appeared to follow changes in air temperature. The fiber optic sensing also showed the overall intensity of the bugs’ noise over the course of the testing period. The signal decreased over time, as the cicadas’ sounds peaked and then faded as they approached the conclusion of their reproductive period.

“We think it is really exciting and interesting that this new technology, designed and optimized for other applications and seemingly unrelated to entomology, can support entomological studies,” said Ozharar. 

Fiber optic sensors are multifunctional, so they can be installed and used for any number of purposes, detecting cicadas one day and some other disturbance the next. They could also be used to detect a variety of different insects, according to Ware. 

“Periodical cicadas were a noisy cohort that was picked up by these systems, but it will be interesting to see if annual measurements of insect soundscapes and vibrations could be useful in monitoring insect abundance in an area across seasons and years,” said Ware.  

Brood X cicadas are back underground and will not emerge until 2038. The long gap between their appearances does allow entomologists to make technological leaps in the interim. Using a mobile smartphone or an app was not feasible when Brood X last emerged in 2004, but both technologies heavily documented the 2021 emergence. Fiber optic cables could lead to a similar technological leap in cicada chorus study. 

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Scientists on the South Pacific island of Vangunu have taken pictures of a critically endangered, giant, coconut-eating rat for the first time. The Vangunu giant rat (Uromys vika or U. vika ) is at least twice the size of a common rat, lives in trees, and can reportedly use its teeth to chew through the tough husks of coconuts. It is only known to only inhabit one island in the Solomon Islands. The sighting was reported in a study published November 20 in the journal Ecology and Evolution. 

[Related: Elusive, unusually large tree-dwelling rodent discovered in the Solomon Islands.]

The rat was spotted by a team from University of Melbourne, Solomon Islands National University, and Zaira Village in Vangunu. First described in 2017, it is the first new species of rodent described in the Solomon Islands in more than 80 years. The deep traditional ecological knowledge of the rat from Vangunu’s people was crucial to the discovery.

“For decades anthropologists and mammalogists alike were aware of this knowledge, but periodic efforts to scientifically identify and document this species were fruitless,” study co-author and University of Melbourne mammalogist Tyrone Lavery said in a statement.

Co-author Kevin Sese from the Solomon Islands National University said that the field work was guided by this local knowledge. The team used camera traps to capture 95 images of four different individuals in their forest habitat.

“The knowledge is with the people. They are the custodians of the local knowledge,” Sese told The New York Times. “If it weren’t for them we wouldn’t have known where to place the cameras.”

U. vika is considered critically endangered due to logging of its lowland forest habitat. The images show it living in Zaira’s primary forests. These are ancient forests that have remained relatively undisturbed by humans. The lands and particularly the Dokoso tribal area represent the rat’s last remaining habitat, but logging has remained central to the economy of the island. 

“Capturing images of the Vangunu giant rat for the first time is extremely positive news for this poorly known species,” Lavery said. “This comes at a critical juncture for the future of Vangunu’s last forest–which the community of Zaira have been fighting to protect from logging for 16 years.”

[Related: Rats can’t barf—here’s why.]

Zaira has been battling to have this patch of forest recognized and protected under the Solomon Islands Protected Areas Act 2010. While the Zaira community were adamant that this enormous rodent species lived in their forests, the rats had never been documented in a scientific journal until now. Confirming the presence could be a vital part of conservation efforts for Vangunu.

“We thank the community of Zaira for [their] unwavering commitment to conserve their forests and reefs in the face of continuous attempts to undermine this commitment, and for their support of this research,” Lavery said. “We hope that these images of U. vika will support efforts to prevent the extinction of this threatened species, and help improve its conservation status.”

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The newts of the genus Taricha come armed with a powerful neurotoxin that they excrete from their skin called tetrodotoxin. The toxin is a chemical defense used against predators. In a study published November 28 in the journal Frontiers in Amphibian and Reptile Science, a team of biologists describes how female Taricha newts produce more tetrodotoxin than males. The findings suggest that tetrodotoxin is not only a line of defense, but also a kind of signal. 

[Related: Poisonous animals probably took their sweet time developing unappetizing bright colors.]

“It had long been considered that newts’ toxin concentrations do not change in their lifetime and that males and females tend to have the same toxin concentrations. Now, we have shown that female newts actually contain more toxin than male newts,” study co-author and University of California, Davis ecologist and evolutionary biologist Gary Bucciarelli said in a statement. “We observed significantly greater and more drastically fluctuating toxin concentrations in females, which may have numerous causes, like mate selection.”  

Totally toxic traits

Tetrodotoxin is also found in the deadly blue-ringed octopus, pufferfish, and some shellfish and amphibian species. In sexually reproducing animals, sexually dimorphic traits like canine tooth size and vibrant color can be a key to reproductive fitness and their survival. These differing traits are believed to increase an individual’s chances of producing the next generation of offspring.

Scientists already knew that Taricha newts had other sexually dimorphic traits, such as mass, size, and tail height, so they were curious to see if toxin production also differed between the sexes. 

In the study, the authors took tetrodotoxin samples from more than 850 newts across 38 different sites in California. They noted the sex, size, mass, and tail height for all of the animals, and if the female newts were pregnant. The newts that had been captured and released were also marked so that they could know if they had been previously sampled. 

Next, the team analyzed their skin to quantify how much of the toxin was found in males compared to females. They also looked at the relationship between sexually dimorphic variables  like size and tail height and how toxin levels changed at the study sites where they could sample more than once across the breeding season. 

Understanding how these toxins work could help biologists understand more about the newts’ reproductive strategies and aid in conservation measures. A recent study found that two out of five amphibians are threatened with extinction and they continue to be the most threatened class of vertebrates on Earth. 

Femme fatale

The authors found that the females carried more toxins than the male newts. While tetrodotoxin levels generally fluctuated in both sexes, the change in females’ levels of toxin was larger. This means that female newts are likely more dangerous than males. 

[Related: How we can help the most endangered class of animals survive climate change.]

“For would-be predators, these higher concentrations pose a serious threat,” said Bucciarelli. “Taricha newts should not be handled unless by knowledgeable personnel, because they can contain up [to] 54 milligrams of tetrodotoxin per individual. Doses up to 42 micrograms per kilo of bodyweight can lead to hospitalization or death.”

The tetrodotoxin also appeared to interact with some of the other sexually dimorphic traits. The heavier newts produced higher levels of the toxin than the lighter newts and the median concentration of toxin was always higher in females regardless of size or weight. The physical resources needed to produce the toxin are possibly invested differently by females than males. Their skin may also be able to carry more of the toxin.

The higher levels of tetrodotoxin might protect females that are vulnerable to predators while reproducing. It could also allow the females to transfer toxin-producing bacteria to their eggs to potentially protect their offspring from snakes. 

Poison patterns

Previously, tetrodotoxin was believed to just be a defense against snakes. The differing amount between the sexes suggests that there might be more to it. The aroma due to the higher concentrations of the toxin may be a cue that helps the newts decide where they look for mates and which mates they choose. 

“Taricha newts’ breeding patterns are highly dependent on precipitation patterns. Given the drought conditions of California, we did not always have a balanced design when field sampling,” said Bucciarelli. “However, we feel the pattern is still very strong. Our next plan is to explore how drought and fire affect newts and their toxin concentrations and how each sex responds to these natural disasters.”

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On November 25, a healthy male Sumatran rhinoceros was born at a western Indonesian sanctuary. This birth is welcome news for the critically endangered species. There are less than 50 Sumatran rhinos left, according to the World Wildlife Fund (WWF) and the International Union for Conservation of Nature (IUCN).

[Related: Rhino horns are shrinking, and humans are to blame.]

A seven-year-old female rhino named Delilah gave birth to the 55 pound calf at the Sumatran Rhino Sanctuary in Way Kambas National Park (SRS TNWK) on the island of Sumatra. According to officials from the sanctuary, a conservation guard found her laying next to her calf early on Saturday morning. The birth was about 10 days before the baby’s expected due date. The baby’s father is a rhino named Harapan who was born at the Cincinnati Zoo and Botanical Garden in Ohio before coming to Sumatra. 

“You never know if a first-time mom will know what to do, but Delilah brought that calf into the world and started nursing it with no fuss or fanfare. It’s an incredible event that gives hope to the future of this critically endangered species,” International Rhino Foundation executive director Nina Fascione said in a press release. 

Sumatran rhinos are the smallest of all rhino species at about 1,000 to 2,100 pounds and three to four feet tall. They have two horns that are dark gray to black. The horns are usually very smooth and form a slender cone that is curved backwards in the wild. Poaching, illegal trading of rhino horns, and climate change have pushed these mammals to the brink of extinction. According to the IUCN Red List, they are currently extinct in Bangladesh, Bhutan, Brunei, Cambodia, India, Laos, Malaysia, Thailand, and Vietnam, according to the Red List. It is uncertain if they are still present in Myanmar. 

Successful births like this one are also rare. In 2012, a male rhino named Andatu born at Way Kambas became the first Sumatran rhino born in an Indonesian sanctuary in over 120 years.

“Two years ago there was only one captive Sumatran rhino pair in the world able to successfully produce offspring. Now there are three pairs–six rhinos–who are proven breeders. Those are much better odds for the long-term survival of this species,” said Fascione.

According to Indonesian Environment and Forestry Minister Siti Nurbaya Bakar, this still-to-be-named calf is the fifth born under a semi-wild breeding program at the park. The new addition brings the rhino herd at Way Kambas up to 10 animals and follows the birth of another calf in September. 

[Related: Rhinos pay a painful price for oxpecker protection.]

The sanctuary is part of a special zone in the national park where all of the rhinos are protected and looked after by local experts.

“The main objective is to produce Sumatran rhino calves to maintain the survival of the Sumatran rhino species which is now threatened with extinction,” sanctuary Director General of Natural Resources and Ecosystem Conservation Satyawan Pudyatmoko said in a statement. “The Sumatran rhino calves are the result of a breeding program. In the future, at SRS TNWK they can be released back into their natural habitat.”

Veterinarians from the Rhino Foundation of Indonesia (Yayasan Badak Indonesia) and animal care staff will continue to closely monitor Delialah and her new calf as they bond.

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The assortment of black dots that decorate African penguins’ mostly all-white fronts might help the birds tell each other apart. This is the first documented time that animal behaviorists and psychologists have pinpointed a physical feature that a bird species uses for visual recognition. The findings are described in a study published in the January 2024 issue of the journal Animal Behaviour.

[Related: How African penguins continue to survive changes in climate.]

In birds, distinguishing individual flock members is primarily based on auditory cues and not visual cues. For example, some parrots distinguish their offspring with squawking equivalent of individual names. This new research is one of the first studies to show that birds could use visual cues more than scientists previously believed. 

According to study co-author and animal psychologist Luigi Baciadonna, the dots on African penguins appear when they are about three to five months old. These birds molt annually and reemerge in the same position when the new plumage comes in. 

In the new study, a team from Italy’s University of Turin, the University of Oulu in Finland, and Zoomarine Italia marine park near Rome conducted a simple experiment with 12 penguins. The team built a small enclosure with plywood walls that was just tall enough to prevent a penguin from seeing over it. They placed cameras on either end of the pen and life-size pictures of two penguins on one of the far walls. One penguin entered the enclosure, where one of the pictures featured its specific mate. 

African penguins form lifelong bonds with their partners and the team tracked their responses to images of other penguins from their species. They found that the penguins spent more time looking at the picture of their partner than they did a picture of a different familiar penguin. This occurred even when the heads of the penguins were blurred. 

When the test penguins were shown two images of their partner, including one that had the spots removed, they preferred the images where the dots remained intact. However, this preference for their partner did not occur when the birds saw unspeckled versions of their mate and a different bird. According to the team, this suggests that the penguins use these spots to tell one another apart.

[Related: Jackass penguins talk like people.]

African penguins live along the coasts of Namibia and South Africa. They are about 24 to 27 inches tall and eat squid, anchovies, and other small fish. African penguins are known to be particularly communicative with one another, so scientists have studied their behavior to better understand some of the more advanced social behaviors seen in primates. A 2021 study found that African penguins are capable of vocal accommodation. Different group members have a different dialect and vocal accommodation allows group members to learn to speak more like the others. 

“Given how goofy penguins can seem–almost stumbling over their feet as they walk, for example–the birds may not seem like they are all that bright,” Baciadonna told New Scientist. “But we showed in these two or three experiments that actually they are quite complicated and complex. They’re also clever.”

Animal physiologist and director of the Institute of Neurobiology at the University of Tübingen Andreas Nieder told Science, “It is an original study with a remarkable finding.” Nieder was not involved in the new research.

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Geologists have discovered 10 new species of trilobite in a relatively unstudied area of Thailand. These extinct sea creatures were hidden for 490 million years and are helping scientists create a new map of the animal life during the late Cambrian period. They are described in a monograph that was published in October in the journal Papers in Palaeontology.

[Related: These ancient trilobites are forever frozen in a conga line.]

Trilobites were marine arthropods similar to today’s spiders and crustaceans and are known for a wide variety of body designs. A species called Walliserops may have jousted with ‘tridents’ on their heads to win mates and recent trilobite specimens have been found with full stomachs. More than 20,000 species lived in Earth’s seas before they went extinct about 250 million years ago.

The trilobite fossils described in the new paper were trapped between layers of petrified ash in sandstone and were the product of old volcanic eruptions. The sediment from the eruptions settled on the bottom of the sea and formed a green layer called a tuff. This important layer contains crystals of a critical mineral that formed during the eruption called zircon. Aside from being as tough as steel, zircon is chemically stable and heat and weather resistant. Zircon also persists while the minerals in other kinds of rocks erode over time. Individual atoms of uranium that transform into lead live inside these resilient zircon crystals and give paleontologists a benchmark for dating the fossils. 

“We can use radio isotope techniques to date when the zircon formed and thus find the age of the eruption, as well as the fossil,” study co-author and University of California, Riverside geologist Nigel Hughes said in a statement.

Finding tuffs from the late Cambrian period (between 497 and 485 million years ago) is also rather rare. According to the team, it is one of the “worst dated” intervals of time in Earth’s history.

“The tuffs will allow us to not only determine the age of the fossils we found in Thailand, but to better understand parts of the world like China, Australia, and even North America where similar fossils have been found in rocks that cannot be dated,” study co-author and Texas State University geologist Shelly Wernette said in a statement. Wernette previously worked in the Hughes Lab.

The trilobite fossils were found on the coast of an island called Ko Tarutao. This island is part of a UNESCO geopark site that has encouraged international teams of scientists to work in this area. 

One of the most interesting discoveries was 12 types of trilobites that scientists have seen in other parts of the world, but not in Thailand. 

“We can now connect Thailand to parts of Australia, a really exciting discovery,” said Wernette.

During trilobites’ lifetime, this area was located on the margins of an ancient supercontinent called Gondwanaland. The giant land mass included present day India, Africa, South America, Australia, and Antarctica. 

[Related: Ancient ‘weird shrimp from Canada’ used bizarre appendages to scarf up soft prey.]

“Because continents shift over time, part of our job has been to work out where this region of Thailand was in relation to the rest of Gondwanaland,” Hughes said. “It’s a moving, shape shifting, 3D jigsaw puzzle we’re trying to put together. This discovery will help us do that.”

They named one of the newly discovered species Tsinania sirindhornae in honor of Thai Royal Princess Maha Chakri Sirindhorn, for her dedication to developing the sciences in Thailand.

“I also thought this species had a regal quality. It has a broad headdress and clean sweeping lines,” Wernette said.

If the team can get an accurate date from the tuffs that the remains of T. sirindhornae had been sitting in for millions of years, they could be able to determine if closely related species found in northern and southern China are roughly the same age. 

The team believes that the portrait of the ancient world hidden in these trilobite fossils contain invaluable information about our planet’s history.

“What we have here is a chronicle of evolutionary change accompanied by extinctions. The Earth has written this record for us, and we’re fortunate to have it,” Hughes said. “The more we learn from it the better prepared we are for the challenges we’re engineering on the planet for ourselves today.”

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It’s been a wormy, sexual head-scratcher for years. The Japanese green syllid worm Megasyllis nipponica detaches its butt in order to reproduce. But how do these algae-eating invertebrates do this? The process could come down to some developmental genes, according to a study published November 22 in the journal Scientific Reports.

[Related: The jumping worm invasion may be less worrisome than it sounds.]

Bye bye, butt

Some segmented sea worms like the syllid worm go through a reproductive process called  stolonization. The stolon is the worm’s posterior organ and it is full of eggs or sperm depending on the worm’s sex. During stolonization, the stolon completely detaches from the rest of the worm’s body for reproduction. 

This detached butt swims around by itself and spawns when it meets another stolon of the opposite sex. This autonomous swimming is believed to protect the original body of the worm from dangers in the environment and help the eggs and sperm travel longer distances. 

In order to swim by themselves, the stolon have to develop their own eyes, antennae, and swimming bristles while still attached to their original body. How this happens has been a mystery. The formation of the stolon itself begins when the gonads near the worm’s butt mature. A head is then formed in the front of the developing stolon, with the eyes, antennae, and swimming bristles following close behind. It develops its nerves and the ability to sense and behave independently before the stolon detaches from the rest of the body.

Hot hox genes

In the new study, a team from the University of Tokyo looked into how the stolon’s head is formed in the first place. The researchers investigated the developmental gene expression patterns in worms as they were sexually maturing. A well-known group of genes that determine body part formation called hox genes help define the head regions of various animals. The team found that hox genes are expressed more in the head region of the stolon. The genes are not typically expressed as much in the middle of the body, except for when the gonads are developing. During this time, the hox genes are highly expressed in the worm’s middle and butt. 

“This shows how normal developmental processes are modified to fit the life history of animals with unique reproductive styles,” study co-author and University of Tokyo marine biologist Toru Miura said in a statement.

[Related: These newly discovered bioluminescent sea worms are named after Japanese folklore.]

Hox genes also determine the segmentation along the worm’s body. The team thought that the hox genes would be expressed differently along the invisible line that runs from the head of the worm to the back end.

“Interestingly, the expressions of Hox genes that determine body-part identity were constant during the process,” said Miura. 

Because of this consistency, the stolon does not have a separatedigestive tract. It also has repeated uniform body segments, except for in its head and tail. 

“This indicates that only the head part is induced at the posterior body part to control spawning behavior for reproduction,” said Miura.

The study showed the developmental mechanism of stolons for the first time and sparked more investigation into this reproductive method. Miura and the team hope to clarify the sex determination mechanism and the endocrine regulations during the worm’s reproductive cycles in future studies.

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If nematodes have nightmares, they might be dreaming about the terror of being eaten alive by a carnivorous fungus called Arthrobotrys oligospora. The very real fungus can sometimes set gooey traps for these worms. It is one of over 700 known species of carnivorous fungi. New findings on the basic processes behind its unique eating habits are described in a study published November 21st in the open access journal PLoS Biology.

[Related: Parasitic Fungi Can Fuse A Nematode’s Gut Into One Cell.]

Nematodes are not usually the first thing on A. oligospora’s menu. The fungus typically gets nutrients from decaying organic matter. Starvation and the presence of nearby worms can prompt this and other fungi to create traps to capture and eat the worms. Another meat eating fungi named Pleurotus ostreatus or the oyster mushroom even uses a nerve gas as its method of trapping down nematodes. 

A. oligospora has a different approach. It generally uses sticky secretions to keep the worms pinned down before they become a meal. Earlier studies have shown some of the biological processes and genetics behind A. oligospora’s predator-prey relationship, but the molecular details of the process have remained generally unclear.

“I think it’s fascinating to consider that right under our feet in the soil, there are micro-predators like A. oligospora are continually evolving new ways to hunt, capture and consume the nematode prey and there is [a] constant evolutionary arms races between these carnivorous fungi and nematodes,” study co-author and molecular biologist Yen-Ping Hsueh tells PopSci. 

To investigate, Hsueh and a team from Academia Sinica in Taipei, Taiwan designed a series of lab experiments to pinpoint the genes and processes involved when A. oligospora preys on a nematode worm species called Caenorhabditis elegans. They used a technique called RNAseq to see the level of activity occurring in various fungus genes at different points in time. When A. oligospora first senses a worm, two separate functions increase–DNA replication and the production of ribosomes. These are the structures that build proteins in a cell. Next, activity increases on many of the genes that encode the proteins that likely help the fungus build and use its traps. These traps include secreted worm-adhesive proteins and a family of proteins the team has identified for the first time.

“The most surprising finding was the dramatic expansion and diversification of the DUF3129 gene family in A. oligospora compared to other fungi,” says Hsueh. “We named members of this family ‘Trap Enriched Proteins’ or TEPs, since they localize to the fungal traps and contribute to trap adhesion and nematode capture.”

After A. oligospora has extended filamentous structures called hyphae into the worm to digest it, the activity in the genes that code for a variety of enzymes called proteases also increases. A group called metalloproteases that break down other proteins is increased even more. The team believes this suggests that A. oligospora uses these proteases to aid in digestion of worms like nematodes.

[Related: Nightmare-fuel fungi exist in real life.]

This research could serve as the foundation for more research into other fungal predator-prey relationships and how A. oligospora feeds on these worms. 

“Our next steps are to further investigate the molecular function of how traps adhere to nematodes,” says Hsueh. “It’s surprising how the traps catch nematodes in such a short time, and the binding of the traps are strong enough that the nematodes almost never get a chance to escape after being trapped.”

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The male sex organs of the animal kingdom come in all shapes and sizes from some that look like a bottle opener to genital stingers. For mammals, penetrative sex with a penis is needed to successfully mate. However, scientists have documented the first non-penetrative sex ever seen in a mammal. The mating technique was observed in the serotine bat (Eptesicus serotinus) and it is described in a study published November 20 in the journal Current Biology.

The mysteries of bat sex

Serotine bats are quite common in Europe and Asia, but the intricacies of bat sex remain elusive. Most previous observations of bats mating have only offered a glimpse of the backs of mating pairs. But in the new study, a team from the University of Lausanne in Switzerland and a bat rehabilitation center in Ukraine got lucky. 

[Related: How echolocation lets bats, dolphins, and even people navigate by sound.]

“By chance, we had observed that these bats have disproportionately long penises, and we were always wondering ‘how does that work?’,” study co-author and University of Lausanne evolutionary biologist Nicolas Fasel said in a statement. “We thought maybe it’s like in the dog where the penis engorges after penetration so that they are locked together, or alternatively maybe they just couldn’t put it inside, but that type of copulation hasn’t been reported in mammals until now.” 

The team placed cameras behind a grid that the bats could climb hoping to get footage of their genitals and mating from one side of the grid. They found that bats’ penises are roughly seven times longer than their partners’ vaginas. Each has a “heart-shaped” head that is also seven times wider than the common bat vaginal opening. This size and shape would make penetration after an erection impossible. The study shows that instead of functioning as a penetrative organ, the penis is more like an extra arm. It pushes the female’s tail sheath out of the way to engage in contact mating, similar to cloacal kissing in birds. Instead of penetration, the birds touch their two rear orifices called the cloaca together for only a few seconds, but long enough for sperm to be released.

The bat sex detectives

Fasel collaborated with bat enthusiast and citizen scientist Jan Jeucker, who filmed hours of footage of the serotine bat in a church attic in the Netherlands. The team analyzed 97 mating events—93 from the Dutch church and four from the Ukrainian bat rehabilitation center. During the recordings, the team did not see a single incidence of penetration. The erectile tissues of the bat penis were completely enlarged before they made any contact with the vulva. The male bats grasped their partner’s nape and moved their pelvis like a probe until it made contact with the vulva. Once contact was made, the pair remained still. These interactions lasted less than 53 minutes on average, but the longest event extended to 12.7 hours. 

After copulation, the researchers saw that the female bats had wet abdomens. They believe this dampness indicates the presence of semen, but more research is needed to confirm if sperm was actually transferred during these assumed mating events.

[Related: What bats and metal vocalists have in common.]

The team also characterized the form of serotine bat genitalia by measuring the erect penises of live bats that were captured as part of other research studies. The necropsies on bats that had died at bat rehabilitation centers revealed how much longer and wider the serotine bat penises were compared to the bat vaginas. The penises are also about a fifth as long as the bats’ head to body length. Female serotine bats also have unusually long cervixes, which potentially helps them select and store sperm.

The team believes that the bats may have evolved their oversized penises as a way to push aside the female tail membranes.  

“Bats use their tail membranes for flying and to capture the insects, and female bats also use them to cover their lower parts and protect themselves from males,” said Fasel. “But the males can then use these big penises to overcome the tail membrane and reach the vulva.”

The team plans to study bat mating behavior in more natural contexts and further investigate penis morphology and mating behavior in other bat species. 

“We are trying to develop a bat porn box, which will be like an aquarium with cameras everywhere,” says Fasel.

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Cooperation between different groups of humans lies at the root of our social norms, traditions, and culture. Groups of a great ape species called bonobos may also work collaboratively with other cliques, according to a study published November 16 in the journal Science.

[Related: Bonobo ladies get to choose their mates and boy oh boy are they picky.]

Along with chimpanzees, bonobos are some of our closest living relatives. Studying their relationships can help scientists reconstruct what human traits appear to be more innate and how they evolve. However, both species of primate exhibit different levels of cooperation despite living in similar social groups that have multiple adult members of both sexes. 

Chimpanzees appear to have more hostile relationships between different groups. Even lethal aggression is not uncommon. This hostility has led researchers to assume that group conflict is an innate part of human nature. 

Bonobos might be telling a different story about how social structures and communities have evolved over time. 

“The ability to study how cooperation emerges in a species so closely related to humans challenges existing theory, or at least provides insights into the conditions that promote between-group cooperation over conflict,’ study co-author and German Primate Center evolutionary biologist Liran Samuni said in a statement.

The study looked at two groups of 31 wild adult bonobos in the Kokolopori Bonobo Reserve in the Democratic Republic of Congo over a period of two years. When the different groups of bonobos met up, they often fed, rested, and traveled together. 

“Tracking and observing multiple groups of bonobos in Kokolopori, we’re struck by the remarkable levels of tolerance between members of different groups,” Samuni said. “This tolerance paves the way for pro-social cooperative behaviors such as forming alliances and sharing food across groups, a stark contrast to what we see in chimpanzees.” 

The authors also did not observe disputes that led to the lethal aggression that has been observed in chimpanzees. The bonobos did not not interact randomly between groups. Cooperation only happened among a select few group members. 

“They preferentially interact with specific members of other groups who are more likely to return the favor, resulting in strong ties between pro-social individuals,” study co-author and Harvard University evolutionary biologist Martin Surbeck said in a statement. “Such connections are also key aspects of the cooperation seen in human societies. Bonobos show us that the ability to maintain peaceful between-group relationships while extending acts of pro-sociality and cooperation to out-group members is not uniquely human.”

[Related: Humans owe our evolutionary success to friendship.]

Cooperation between human groups leads to exchanges of ideas, knowledge, innovation, and resources. The Bonobos in the study also shared food resources across groups without any strong cultural influence. The authors believe that this challenges another existing idea that a shared culture and traits are necessary components for groups to cooperate with one another. 

The study also highlights the importance of collaboration when studying bonobos that live in remote and largely inaccessible parts of the preserve. 

“It is through strong collaborations with and the support of the local Mongandu population in Kokolopori, in whose ancestral forest the bonobos roam, that studies of this fascinating species become possible,” said Subeck, who directs research in the Kokolopori Bonobo Reserve. “Research sites like Kokolopori substantially contribute not only to our understanding of the species’ biology and our evolutionary history, but also play a vital role in the conservation of this endangered species.”

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Like jellyfish, fungi, sea worms, and fireflies, some species of sea cucumbers glow in the dark. A team of researchers from Nagoya University in Japan have found that 10 known deep-sea species are bioluminescent in their natural habitats. The findings are part of a new textbook called The World of Sea Cucumber published on November 10.

[Related: The deepest known ocean virus lives under 29,000 feet of water.]

There are roughly 1,200 species of sea cucumbers. These marine invertebrates are found in every ocean on Earth, but they are best represented in the western Pacific and Indian Ocean. They generally live in shallow waters, but some species live at depths of thousands of feet deep. Most closely related to sea urchins, sea stars (aka starfish), sea lilies, and sand dollars, these bottom-dwellers range from as small as one inch long up to six feet. Some sea cucumbers are also known to shoot out a tangle of sticky, noodle-like goo from their butts when provoked. 

The new textbook takes readers deep underwater and discusses the bioluminescent properties of some of these sea cucumbers. According to NOAA, the light emitted by bioluminescent animals is produced by energy released from interior chemical reactions that are sometimes ejected from the organism. Its function is still a mystery, but it is generally used to ward off or evade predators, find food, or as a form of communication. 

The authors drew on previous sea cucumber research to highlight the differences between the shallow-dwelling and a bit more drab species and their brilliantly glowing deep-sea relatives. The book also shows the evolution of sea cucumbers from the Jurassic era roughly 180 million years ago up to the present day. 

To uncover the 10 bioluminescent sea cucumber species, the team deployed a remotely operated vehicle about 3,280 feet below the surface of Monterey Bay, California. The vehicle was equipped with a very sensitive and an arm that was robotically controlled from the ship. Unlike the more uniform bioluminescence seen in specimens taken onto ships, the light was shining from the sea cucumber’s head to tail and then back up similar to a wave.  

According to the authors, the previously unknown luminosity in these 10 deep-sea species suggests that sea cucumbers are more diverse than scientists once believed. A member of the order Molpadia is included in this discovery, which was previously believed to be a non-luminescent order of animals. 

While these sea cucumbers dwell in some of Earth’s deepest parts, they are still not immune to the effects of overfishing and particularly the drilling and mining activities that threaten their ecosystem. 

[Related: This headless chicken is the deep-sea ‘monster’ of our dreams.]

“As deep-sea exploration and development continue, information on their biodiversity and ecology, such as this book, becomes important as it allows us to assess the impact of human activities on deep-sea ecosystems,” textbook co-author and Nagoya University biochemist Manabu Bessho-Uehara said in a statement. “Heavy metal pollution from the mud discarded during drilling operations and motor-derived noise disrupting sound communication are important problems, but the effects on organisms when bioluminescence signals are disturbed, such as when light is obscured by drilling mud, have not been examined. It is necessary to clarify the importance of bioluminescence on the deep-sea floor and find measures that will lead to sustainable development.”

Studying the flora and fauna living in these extreme locations can also provide valuable knowledge of all life on Earth. It can help us discover new viruses that thrive in hydrothermal vents and the factors at play in Earth’s climate and carbon cycle. 

“I believe that understanding deep-sea ecosystems and interactions among organisms will lead to a better understanding of life on Earth itself,” said Bessho-Uehara.

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For the first time in over 60 years, a rare egg-laying mammal has been spotted by scientists. Attenborough’s long-beaked echidna (Zaglossus attenboroughi) was caught on camera during a major expedition in the Cyclops Mountains in Indonesia’s Papua Province.

[Related: Dams are hurting this enigmatic Australian species.]

A sacred animal

The long-beaked echidna is named for wildlife documentarian and conservationist Sir David Attenborough and has only been recorded by scientists once in 1961. It is considered a monotreme, or an evolutionary distinct group of mammals who can lay eggs. The platypus is also a monotreme and there are only five remaining species of these strange types of mammal on Earth. 

They live in burrows and mainly eat insects, earthworms, and termites. They are listed as Critically Endangered on the IUCN Red List of Threatened Species and are only known to live in the Cyclops Mountains.

“Attenborough’s long-beaked echidna has the spines of a hedgehog, the snout of an anteater, and the feet of a mole. Because of its hybrid appearance, it shares its name with a creature of Greek mythology that is half human, half serpent,” University of Oxford biologist James Kempton said in a statement. “The reason it appears so unlike other mammals is because it is a member of the monotremes–an egg-laying group that separated from the rest of the mammal tree-of-life about 200 million years ago.”

The echidna also has cultural significance for the people in the village of Yongsu Sapari. They have lived on the northern slopes of the Cyclops Mountains for eighteen generations. Rather than fighting during conflicts, the tradition is for one party to go up into the Cyclops to find echidna while the other party goes to the ocean to search for a marlin. Both of these creatures were difficult to find and it would take decades to even whole generations to locate them. However, once they were found, the marlin and echidna would symbolize the end of the conflict.

Finding echidnas, whip scorpions, and forest shrimp

During an expedition that began in 2019, a group of scientists from institutions in multiple countries set up over 80 trail cameras. They did not see any signs of the echidna for four weeks of trekking through a “beautiful but dangerous land.” A sudden earthquake forced the team to evacuate, one team member broke his arm in two places, another contracted malaria, and another had a leech attached to his eye for a day and a half.

[Related: Meet the first electric blue tarantula known to science.]

On the last day of the expedition, they finally spotted Attenborough’s long-beaked echidna. The identification of the species was later confirmed by mammalogist Kristofer Helgen from the Australian Museum Research Institute.

In addition to this elusive egg-laying mammal, this expedition marked the first comprehensive assessment of mammal, reptile, amphibian, and invertebrate life in the Cyclops Mountains. They combined Western scientific techniques with the extensive local knowledge of Papuan team members. Among the new discoveries are several insect species that are completely new to science and an entirely new genus of ground and tree-dwelling shrimp.

“We were quite shocked to discover this shrimp in the heart of the forest, because it is a remarkable departure from the typical seaside habitat for these animals,” entomologist  Leonidas-Romanos Davranoglou from the Oxford University Museum of Natural History said in a statement. “We believe that the high level of rainfall in the Cyclops Mountains means the humidity is great enough for these creatures to live entirely on land.”

Some other funky underground species including blind spiders, blind harvestman, and a whip scorpion were also found living in a previously unexplored cave system. The team hope that its rediscovery of Attenborough’s long-beaked echidna and all of these new species will help bring attention to the conservation needs of the Cyclops Mountains and Indonesian New Guinea.

CORRECTION November 19, 2023 3:55 PM EST: An earlier version of the article summary said the animal was named after Richard Attenborough. Zaglossus attenboroughi is named for Sir David Attenborough. We regret the error.

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Researchers in Denmark have discovered six new species of beetle, including one with some eye-opening genitalia. Loncovilius carlsbergi has a penis shaped like a bottle opener. The top looks like the protruding longer part of a bottle opener that latches onto the bottle cap, and the bottom resembles the pincer that holds the bottle in place. The specimen is described in a study published October 28 in the Zoological Journal of the Linnean Society.

[Related: Acrobatic beetle bots could inspire the latest ‘leap’ in agriculture.]

While the team from the Natural History Museum of Denmark still not sure why Loncovilius carlsbergi evolved this uniquely shaped penis, studying them can reveal the role that the genitals play in the bugs’ daily lives. 

“Genitalia are the organs in insects that evolve to be different in every species. As such, they are often the best way to identify a species,” study co-author and biologist Aslak Kappel Hansen said in a statement. “That’s why entomologists like us are always quick to examine insect genitalia when describing a species. The unique shape of each species’ genitals ensures that it can only reproduce with the same species.”

Aslak and his colleagues found and named six new species in the rove beetle genus Loncovilius that had been hidden within the insect collections at the museum. Loncovilius carlsbergi was named for the Carlsberg Foundation, which has funded research at the museum for years. Carlsberg is a popular 176-year-old Danish beer company.

Loncovilius beetles are only found in Chile and Argentina and entomologists don’t know too much about them. They are less than an inch long and all of their legs have sticky bristles on them, while other predatory rove beetles only have sticky front legs. 

Where Loncovilius beetles live make them special among this family of beetles. Most predatory rove beetles live on the ground, among dead leaves, fungi, and bark. Loncovilius beetles live on flowers. The authors believe that their sticky legs helped them adapt the ability to climb flowers and vegetation.

“We suspect that they play an important role in the ecosystem. So, it’s worrying that nearly nothing is known about this type of beetles, especially when they’re so easy to spot–and some of them are even quite beautiful,” study co-author and systematic entomologist Josh Jenkins Shaw said in a statement. “Unfortunately, we can easily lose species like these before they’re ever discovered.”

The forces of climate change, pollution, and habitat loss is exacerbating the Earth’s biodiversity crisis. These combined forces have threatened over one million plant and animal species with extinction, a rate of loss that is 1,000 times greater than previously expected. The team believes that this crisis will likely affect these newly discovered beetles as well.

[Related: A pocketful of bacteria helps these beetles through their most dramatic life changes.]

“Loncovilius populations are likely to change in coming decades. Our simulations demonstrate that at least three of the Loncovilius species are at risk because the rapidly changing climate strongly alters more than half of their habitat area by 2060,” study co-author and PhD student José L. Reyes-Hernández said in a statement. “It is important to stress that many more species will be affected by this change, but we don’t know how because only for four species we had enough data for our analysis.” 

The planet’s species are also going extinct faster than scientists can fully name and describe them. Some estimates place the number of species lost from the Earth every day at upwards of 150. According to Jenkins Shaw, as many as 85 percent of all species on the planet are still not formally named or described. 

“A taxonomic name is important because nature conservation relies on knowledge about species in particular areas. Without such a description, species are often left out of conservation efforts,” said Jenkins Shaw.

The authors hope that Loncovilius carlsbergi’s attention-grabbing genitals could spark broader interest in insects. They are also working on producing an actual bottle opener shaped like this beetle’s penis into production. 

“It’s important that we recognize the vast wealth of yet to be researched species around us before it’s too late. We would like for people around the world to talk about the crisis facing our planet’s species. A move towards serious learning and awareness may be sparkled by a light chat that takes place over a beer,” said Kappel Hansen.

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This article was originally featured on Knowable Magazine.

More than 1.5 billion years ago, a momentous thing happened: Two small, primitive cells became one. Perhaps more than any event—barring the origin of life itself—this merger radically changed the course of evolution on our planet.

One cell ended up inside the other and evolved into a structure that schoolkids learn to refer to as the “powerhouse of the cell”: the mitochondrion. This new structure provided a tremendous energetic advantage to its host—a precondition for the later evolution of complex, multicellular life.

But that’s only part of the story. The mitochondrion is not the only important structure within complex, eukaryotic cells. There’s the membrane-bound nucleus, safekeeper of the genome. There’s a whole system of internal membranes: the endoplasmic reticulum, the Golgi apparatus, lysosomes, peroxisomes and vacuoles—essential for making, transporting and recycling proteins and other cargo in and around the cell.

Where did all these structures come from? With events lost in the deep past and few traces to serve as evolutionary clues, it’s a very tough question to tackle. Researchers have proposed various hypotheses, but it is only recently, with some new tools and techniques, that cell biologists have been able to investigate the beginnings of this intricate architecture and shed some light on its possible origins.

A microbial merger

The idea that eukaryotes originated from two cells merging dates back more than 100 years but did not become accepted or well known until the 1960s, when the late evolutionary biologist Lynn Margulis articulated her theory of endosymbiosis. The mitochondrion, Margulis said, likely originated from a class of microbes known as alphaproteobacteria, a diverse group that today includes the bacterium responsible for typhus and another one important for the genetic engineering of plants, among many others.

Nothing was known about the nature of the original host cell. Scientists proposed that it already was fairly complicated, with a variety of membrane structures inside it. Such a cell would have been capable of engulfing and ingesting things—a complicated and energetically expensive eukaryotic feature called phagocytosis. That might be how the mitochondrion first got into the host.

But this idea, called the “mitochondria late” hypothesis, doesn’t explain how or why the host cell had become complex to begin with.

In 2016, evolutionary biologist Bill Martin, cell biologist Sven Gould and bioinformatician Sriram Garg, at the University of Dusseldorf in Germany, proposed a very different model known as the “mitochondria early” hypothesis. They argued that since no primitive cells today have any internal membrane structures, it seems very unlikely that a cell would have had these over 1.5 billion years ago.

Instead, the scientists reasoned, the endomembrane system—the whole hodgepodge of parts found inside complex cells today—could have evolved soon after the alphaproteobacterium took up residence inside a relatively simple host cell, of a kind from a class called archaea. The membrane structures would have arisen from bubbles, or vesicles, released by the mitochondrial ancestor.

Free-living bacteria shed vesicles all the time, for all sorts of reasons, Gould, Garg and Martin note, so it seems reasonable to think they’d continue to do that when enclosed inside a host.

Eventually, these vesicles would have become specialized for the functions that membrane structures perform today inside eukaryotic cells. They would even fuse with the host cell’s membrane, helping to explain why the eukaryote plasma membrane contains lipids with bacterial features.

Vesicles could have served an important initial function, says biochemist Dave Speijer of the University of Amsterdam. The new endosymbiont would have generated plenty of poisonous chemicals called reactive oxygen species, by oxidizing fatty acids and burning them for energy. “These destroy everything, they are toxic, especially on the inside of a cell,” Speijer says. Sequestering them inside vesicles would have helped keep the cell safe from harm, he says.

Another problem created by the new guest could also have been helped by making membranes barriers, Gould, Garg and Martin add. After the alphaproteobacterium arrived, bits of its DNA would have mixed with the genome of the archaeal host, interrupting important genes. Fixing this would mean evolving machinery to splice out these foreign pieces—today they’re known as introns—from the messenger RNA copies of genes, so those protein-making instructions wouldn’t be garbled.

But that created yet another problem. The protein-making machinery—the ribosome—works extremely fast, joining several amino acids together per second. In contrast, the intron-removing system of the cell is slow, snipping out about one intron per minute. So unless the cell could keep the mRNA away from ribosomes until the mRNA was properly processed, the cell would produce many nonsensical, useless proteins.

The membrane surrounding the nucleus provided an answer. Serving as a spatial barrier, it allows mRNA splicing to finish up in the nucleus before the intron-free mRNA is translated in the cell’s internal fluid, the cytosol. “This is the selective pressure behind the origin of the nucleus,” Martin says. To form it, vesicles secreted by the endosymbiont would have flattened and wrapped around the genome, creating a barrier to keep ribosomes out but still allowing small molecules to pass freely.

An inside-out explanation

In short, Gould, Garg and Martin’s hypothesis explains why endomembrane compartments evolved: to solve problems created by the new guest. But it doesn’t fully explain how the alphaproteobacterium got inside the host to begin with, says cell biologist Gautam Dey at EMBL in Heidelberg, Germany; it assumes the endosymbiont is already inside. “This is a massive problem,” Dey says.

An alternative idea, proposed in 2014 by cell biologist Buzz Baum of University College London (with whom Dey once worked) and his cousin, University of Wisconsin evolutionary biologist David Baum, is the “inside-out” model. In this scenario, the alphaproteobacterium and the archaeal cell destined to be its eventual host would have lived side by side for millions of years in an intimate symbiosis, each depending on the other’s metabolic products.

The archaeal cell would have had long protrusions, as seen on some modern-day archaea that live in close association with other microbes. The alphaproteobacterium would have nestled up against these slender extensions.

Eventually, the protrusions would have wrapped around the alphaproteobacterium and enclosed it completely. But during the long stretch of time before that happened, the archaeal cell would have begun some spatial division of labor: It would keep information-processing jobs in its center, where the genome was, while functions like protein building would take place in the cytosol within the protrusions.

The power of the inside-out model, Buzz Baum says, is that it gives the cell eons of time, before the alphaproteobacterium becomes fully enclosed, to evolve ways to regulate the number and size of the mitochondrion and other membrane compartments that would eventually become fully internal. “Until you can regulate them, you’re dead,” Buzz Baum says.

The model also explains why the nucleus has the shape that it does; in particular, it provides an explanation for its unusually large pores. Viewed from inside the center of an archaeal cell, the long protrusions would be openings that could naturally become big pores like those, Baum says.

Most important, the inside-out model explains how the alphaproteobacterium would have gotten inside the archaeal host in the first place.

Still, the inside-out model has features it needs to explain. For example, the mitochondrion would end up in the wrong place—inside the endoplasmic reticulum, the network of tubes on which sit the cell’s protein-making ribosomes, as the archaeal protrusions wrapped around it. And so an additional step would be required to get the alphaproteobacterium into the cytoplasm.

But Martin’s main objection is that the inside-out model does not provide an evolutionary pressure that would have caused the nucleus or other membrane-bound compartments to arise in the first place. The inside-out model “is upside-down and backwards,” Martin says.

The nucleus: A riddle in the middle

Though the models agree that the mitochondrion evolved from an alphaproteobacterium, they have very different ideas about the origin of the nucleus and other organelles.

In the Gould, Garg and Martin model, the source for all of the structures would have been vesicles released by the evolving mitochondrion. Vesicles to contain reactive chemicals or cellular cargo, and the ability to move this cargo around, would have evolved very early. The nucleus would have come later.

In the inside-out model, the nucleus was, essentially, the remains of the archaeal cell after it wrapped its membranes around the alphaproteobacterium. So it would have appeared immediately. The endoplasmic reticulum also would have formed early, created from those squished-together protrusions. Other organelles would have come later—arising, Buzz Baum says, from buds of archaeal membrane.

Thus the models also make different predictions about the chemical nature of the membranes of cell organelles—at least originally—and how today’s complex cells came to have membrane lipids that are all chemically like the ones in bacteria, not archaea.

In the Gould, Garg and Martin model, in the beginning all the membranes except for the host cell’s outermost one would have been bacterial, like the membranes of the new resident. Then, as bacterial vesicles fused with this archaeal outer membrane, the bacterial lipids would slowly replace the archaeal ones.

In the inside-out model, the membranes of the nucleus and endoplasmic reticulum — and probably others — would have been archaeal, like the host, to start. Only later on, after genes from the bacterial genome moved over to the archaeal genome, would the lipids become bacterial in nature, Baum suggests.

How to test these ideas? Through experiments, cell biologists are starting to glimpse ways in which simple vesicles could have diversified into different organelles with distinct jobs—by taking on different shapes, like the layered membrane stacks of the modern endoplasmic reticulum or the Golgi body, or by ending up with different proteins inside them or on their membranes.

They are also highlighting the dynamism of the modern-day mitochondrion—and its potential to spawn new membrane structures.

Take, for example, the compartment that Speijer thinks evolved early in order to deal with reactive oxygen species: the peroxisome.

In 2017, cell biologist Heidi McBride of McGill University in Montreal reported that cells lacking peroxisomes could generate them from scratch. Working with mutant human fibroblast cells without peroxisomes, her team found that these cells put proteins that are essential for peroxisome function into mitochondria instead. Then the mitochondrial membrane released them as little bubbles, or vesicles.

These vesicles, or proto-peroxisomes, matured into true peroxisomes when they fused with another type of vesicle derived from endoplasmic reticulum, which carry a third necessary peroxisome protein. “It’s a hybrid organelle,” McBride says.

For McBride, this is an indication that peroxisomes—and probably other organelles—originally came from mitochondria (not exclusively from the endoplasmic reticulum, as previously believed). “The presence of mitochondria launched the biogenesis of new organelles,” she says. “In the case of peroxisomes, it’s quite direct.”

Other mitochondrion antics have also been noted.

First, a 2021 report from the lab of biochemist Adam Hughes at the University of Utah found that when yeast cells are fed toxic amounts of amino acids, their mitochondria will shed vesicles that are loaded with transporter molecules. The transporters move amino acids into the vesicles, where they won’t poison the mitochondria.

Hughes also discovered that the vesicles shed by the mitochondria can form long, tubule-like extensions with multiple layers, reminiscent of the layered stacks of the endoplasmic reticulum and the Golgi body. The structures persist in the cell for a long time. “They’re definitely their own unique structure,” Hughes says.

And in 2022, immunologist Lena Pernas, now at UCLA, showed that multilayered, mitochondria-derived structures can form in other contexts, too. When a cell is infected by the parasite Toxoplasma, her team found, the mitochondria surround the parasite and change shape. The parasite responds, and the upshot is that the mitochondrion ends up shedding large bits of outer membrane.

Pernas, who wrote about mitochondrial remodeling in the Annual Review of Physiology in 2016, recently discovered that these structures, which initially look like simple vesicles, also can grow and take on more complex shapes, such as stacks of sheet-like layers. What’s more, the stress of infection changes what sorts of proteins are placed on these shed bits of mitochondrial membrane. Such changes open the door for the stacked sheets to behave in different ways than they normally would, presenting the opportunity to take on new jobs, Pernas says.

The more Pernas and Hughes study these structures—found in quite different cells and conditions—the more similar they look. It’s tantalizing, says Hughes, to imagine how a structure like this, forming in the early days of eukaryote evolution, could have evolved over eons of natural selection into some of the endomembrane compartments existing in cells today.

It may never be possible to know for sure what happened such a very long time ago. But by exploring what can happen in today’s living bacterial, archaeal and eukaryotic cells, scientists can get more clarity on what was possible—and even probable. A cell moves into another cell, bringing benefits but also problems, setting off a complex cascade. And then, McBride says, “all this stuff blooms and blossoms.”

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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Hummingbirds are some of the world’s fastest birds and must frequently squeeze through tiny spaces in plants to get to the nectar that they need to keep up their energy. However, over time, they have lost their ability to fold their wings close to their bodies at the wrist and elbow like other birds. How hummingbirds squeeze into such tight spaces has remained a mystery to ornithologists until now. A study published November 9 in the Journal of Experimental Biology found that they deploy two very specific strategies: the sideways and the bullet.

[Related: This hybrid hummingbird’s colorful feathers are a genetic puzzle.]

Into the flight arena

The study focused on Anna’s hummingbirds (Calypte anna). These are among the most common hummingbirds living along the West Coast of the United States. They are about the size of a ping-pong ball and have iridescent emerald feathers and sparkling pink throat plumage. 

A team from the University of California, Berkeley designed a two-sided flight arena for the experiment. They used alternating rewards to train the hummingbird to fly through a 2.48 square inch gap in the partition that separated the two sides of the arena. To do so, they only refilled a feeder shaped like a flower with a sip of sugar water if the bird returned to the feeder that was on the other side through one of the gaps. This encouraged the birds with an only 4.7 inch-wide wingspan to flit around the arena. 

The team then replaced the gap between the two sides of the flight arena with a series of smaller oval and circular openings that ranged from 4.7 inches to only 2.3 inches in height, width, and diameter. The birds’ movements were recorded using high-speed cameras, to get a sense of how they negotiated the various openings. 

Next, the team wrote a computer program to methodically track the position of each bird’s bill as it approached and passed through each hole. The program also pinpointed where the hummingbird’s wing tips were, to calculate their wing positions as they transited through.

[Related: These female hummingbirds don flashy male feathers to avoid unwanted harassment.]

The experiment revealed that the hummingbirds used two unique strategies to negotiate the gaps. 

The sideways

In the first strategy, the hummingbirds approached the circular opening and usually hovered in front of it to assess its size. They then traveled through it sideways, reaching forward with one wing and sweeping the second wing back, similar to the shape of a cross. Their wings were still fluttering to fly through the door and then swiveled forward to continue on their way. 

The bullet

For the second strategy, the birds swept their wings backwards, pinning them to their bodies. They then quickly shot through the opening beak first like a bullet, before sweeping their wings forward. They resumed flapping their wings once they were safely through the circle. All of the hummingbirds in the study generally deployed this technique as they grew bolder and more familiar with the arena.

Changing tactics

The team observed that the hummingbirds who used the first strategy of sideways traveling tended to fly more cautiously than those that shot through the circles beak first. As the birds became more familiar with the openings after multiple approaches, they appeared to become more confident. They started to approach them quicker and dropped the more sideways way of getting through in favor of shooting through beak first. 

For the smallest opening–only half a wingspan wide–every bird zipped through facing forward with their wings back. Even the more cautious birds did this on their first attempt to avoid collisions. 

According to the team, about eight percent of the birds in the experiment clipped their wings as they passed through the partition and only one experienced a major collision. The bird who did experience the collision was able to successfully reattempting the move and continue flying.  

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For the first time, scientists have observed one virus attaching itself to another virus. An electron microscope captured the interaction in stunning detail and shows how these two different viruses may have co-evolved. The findings were published in the Journal of the International Society of Microbial Ecology on October 31. 

[Related: The deepest known ocean virus lives under 29,000 feet of water.]

The viruses in the study are both categorized as bacteriophages. These are a group of viruses that are known to infect bacteria. Bacteriophages also infect single-celled prokaryotic organisms known as archaea and are commonly called “phages.” 

Some viruses called satellites (shown in purple) depend on both their host organism and another virus known as a helper to complete its life cycle. The satellite virus depends on the helper virus to build the protective shell that covers its genetic material called a capsid or to help it replicate its DNA.  For this relationship to continue, the satellite and the helper must be close to one another for at least a little while, but there were no known cases of a satellite virus attaching to the helper until this discovery. 

“When I saw it, I was like, ‘I can’t believe this,’” study co-author and University of Maryland, Baltimore County biologist Tagide deCarvalho said in a statement. “No one has ever seen a bacteriophage—or any other virus—attach to another virus.”

The students who isolated the satellite nicknamed it the MiniFlayer and dubbed its helper the MindFlayer. The team saw this viral relationship between the satellite MiniFlayer and helper MindFlayer while looking at some samples of a family of bacteriophage satellites that infect Streptomyces bacteria. They initially believed that the samples had been contaminated due to the large sequences of DNA and some smaller sequences of DNA that didn’t match anything they were familiar with. 

They took detailed electron microscopy images that show 80 percent of helper viruses in this sample had a satellite bound at its “neck,” where the helper’s outer shell connects to its tail. The ones that did not still had remnant satellite tendrils at the neck that the team said looked like “bite marks.”

Next, they analyzed the genomes of the bacteriophages and bacterial hosts. The satellite viruses had genes that coded for their outer protein shell, but did not have the genes needed to multiply within bacterial cells. This evidence supported the idea that both types of bacteriophages were actually interacting with each other. 

[Related: Ask Us Anything: Can viruses be good for us?]

They also saw that the satellite viruses did not have a gene that is necessary for them to integrate into the genome of bacterial host cells after they have entered them. Since most of the satellite viruses can hide in the host’s DNA, they can replicate once the right helper comes along. According to the team, the satellite thus attaches to the helper using a unique adaptation at its tail, so that it can survive without this key gene.

 “Attaching now made total sense, because otherwise, how are you going to guarantee that you are going to enter into the cell at the same time? This satellite has been tuning in and optimizing its genome to be associated with the helper for, I would say, at least 100 million years,” co-author and  University of Maryland, Baltimore County computational biologist Ivan Erill said in a statement. 

As of now, this kind of relationship has only been observed in a laboratory setting. Understanding these long-term viral relationships could help scientists discover numerous other examples in nature. 

“It’s possible that a lot of the bacteriophages that people thought were contaminated were actually these satellite-helper systems,” said deCarvalho. “So now, with this paper, people might be able to recognize more of these systems.”

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Dinosaur Mysteries digs into the secretive side of the “terrible lizards” and all the questions that keep paleontologists up at night.

YOU NEVER KNOW how small you are until you’re next to a big ol’ dinosaur. Find the right lighting in the museum hall and you can literally stand in the shadow of the skeletons of Apatosaurus, Patagotitan, Brachiosaurus, and other reptiles that grew far larger than any other terrestrial creature in the past 66 million years. But even after nearly two centuries of research, we have only the haziest notions of why some dinosaurs were larger than any terrestrial mammal to date.

While a number of dinosaurs fell in the supersized category—Tyrannosaurus rex weighed more than a mature male African elephant—the sauropods were the all-time titleholders. They had small heads with simple teeth, impressively long necks, hefty bodies, and tapering tails. So many sauropod species reached more than 100 feet in length, paleontologists still aren’t sure which one stretched the farthest. While the largest land mammals, like the hornless rhino Paraceratherium and the biggest fossil elephants, got to be about 18 tons, sauropods evolved to have more mass at least 36 times during their evolutionary history—an ongoing reprisal of gargantuan herbivores through the Jurassic and Cretaceous.

The stunning heft of these creatures has often led us to wonder why they got to be so much bigger than any terrestrial creature before or since. But in the realm of paleontology, “why” questions are extremely difficult to answer. Queries starting with “why” are matters of history, and in this case, the history plays out dozens of times on multiple continents over the course of more than 130 million years. Though we see the end effect, we can’t quite make out the causes.

Dinosaurs have a habit of digging their claws into our imaginations, however, so researchers have kept on, turning up a few clues in the past two decades about the surfeit of superlative sauropods. While higher oxygen levels have been linked to bigger body sizes in a few ancient insects, the atmosphere in the heyday of the dinosaurs was about the same as today’s. What’s more, the Earth’s gravitational force was just as strong in the Mesozoic era as in the modern era. So we know that the impressive size of Argentinosaurus and other top sauropods was not a matter of an abiotic factor like increased oxygen in the atmosphere or lower gravity. Our explanation lies elsewhere.

Paleontologists are getting closer to the truth by looking at the dinosaurs themselves. For example, experts have identified a suite of characteristics that set sauropods apart from the mastodons and giant rhinos of the Cenozoic. Eggs have a great deal to do with it.

The largest mammals of all time were placentals, gestating their offspring on the inside so they could come out more developed. This reproductive strategy comes with some constraints. To reach even larger adult sizes, females of each species would need to carry their babies in the womb for longer. African elephants, for example, already gestate for about two years—during which much can go wrong. But sauropods, like all nonavian dinosaurs, laid multiple eggs at a time, bypassing the reproductive constraints of live birth and flooding their ecosystems with tons of babies that had the potential to grow huge (even if most ended up as snacks for the carnivores of the time). The different reproductive strategies gave dinosaurs some advantages over mammals.

Camarasaurus and other sauropods also got some assistance from their anatomical peculiarities. Sauropods had complex air-sac systems in their respiratory tracts that created air pockets within and around their bones. These nifty features kept their skeletons light without sacrificing strength, and also made extracting oxygen from the air and shedding excess body heat more efficient. The distinctive dinosaurs could grow long necks too, because they didn’t have heavy heads full of massive, grinding teeth like large herbivorous mammals over the past 66 million years. Instead, sauropods had small, light noggins full of spoon- or pencil-shaped teeth that were mostly just capable of cropping vegetation to be broken down and fermented through their gastrointestinal tracts. In other words, their guts did the work, not their teeth. Studies of ginkgoes, horsetails, and other common Mesozoic plants indicate that the ancient vegetation was more calorie-rich than previously supposed, so the abundance of green food likely fueled the reptilian giants’ unprecedented growth.

But these facts only show us what allowed sauropods to become big. The dinosaurs didn’t have to drift in that direction. In fact, some were relatively small: The island-dwelling species Magyarosaurus was about the size of a large cow. Sauropods could have thrived at smaller sizes, but they instead kept spinning off lineages of giants. We know something about what made living large possible, but what we still don’t know is what evolutionary pressures drove sauropods to evolve enormous bodies.

Predators certainly played their part. All sauropods were born small—even the largest species hatched from eggs about the size of a soccer ball. They were vulnerable to various Jurassic and Cretaceous carnivores, but growing up quickly was one way to stave off those hungry jaws. Hunting megafauna can be dangerous and even deadly, as we see with lions, wolves, and even humans today, and so sauropods may have plumped up to be less appealing to the likes of Allosaurus and T. rex.

But if carnivorous appetites were the main driver of sauropod size, we’d see a more uniform and extended “arms race” between the dinosaurs over time, resulting in gradually larger predators and prey. The fossil record instead shows that sauropods scaled up in different times and places, likely for an array of reasons ranging from local grub to what mating sauropods found sexy in each other. The repeated evolution of gigantic dinosaurs hints that there were many pathways to the sauropods’ impressive stature, not just one. Biology was as complicated back then as it is now, and we’ll never get the full story without experiencing 100-foot-long reptiles ourselves.

Read more PopSci+ stories.

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While the majority of fish are cold-blooded and rely on the temperature outside of their bodies to regulate their internal temperatures, less than one percent of sharks are actually warm-blooded. The extinct but mighty megalodon and the living great white shark generate heat with their muscles the way many mammals do. However, they are not the only sharks with this warm quirk. A study published November 7 in the journal Biology Letters found that there are more warm blooded sharks than scientists initially believed. 

[Related: Megalodons were likely warm-blooded, despite being stone-cold killers.]

Warmer muscles might help these giant carnivores be more powerful and athletic, by using that heat to generate more energy. Regional endothermy in fish has been seen in apex predators like the great white or giant tuna, but there has been debate on when this warm bloodedness evolved in sharks and if the megalodon was warm blooded. A previous study from June 2023 found that the megalodon was warm blooded and that the amount of energy it used to stay warm may have contributed to its extinction about 3.6 million years ago.

The new study looked at the results of autopsies from some unexpected shark strandings in Ireland and southern England earlier in 2023. The sharks belonged to a rarely seen species called the smalltooth sand tiger shark. These sharks are found around the world in temperate and tropical seas and in deep waters (32 to 1,700 feet deep). They have a short and pointed snout, small eyes, protruding teeth, and small dorsal and anal fins and can reach about 15 feet long. Smalltooth sand tiger sharks are considered a “vulnerable” species by the International Union for the Conservation of Nature. While they are not targeted by commercial fisheries, the sharks may be mistakenly caught in nets and may face threats from pollution. 

Smalltooth sand tiger sharks are believed to have diverged from the megalodon at least 20 million years ago. The autopsies from this year’s stranded sharks unexpectedly served as a timeline that took marine biologists from institutions in Ireland, South Africa, and the United States back millions of years. 

The team found that these rare sharks have physical features that suggest they also have regional endothermy like the megalodon, great white, and some filter-feeding basking sharks. This new addition means that there are likely more warm-blooded sharks than scientists thought and that warm bloodedness evolved quite a long time ago.

“We think this is an important finding, because if sand tiger sharks have regional endothermy then it’s likely there are several other sharks out there that are also warm-bodied,” study co-author and marine biologist Nicholas Payne said in a statement. “We used to think regional endothermy was confined to apex predators like the great white and extinct megalodon, but now we have evidence that deep water ‘bottom dwelling’ sand tigers, and plankton-eating basking sharks also are warm bodied. This raises plenty of new questions as to why regional endothermy evolved, but it might also have important conservation implications.” Payne is affiliated with Trinity College in Dublin, Ireland. 

[Related: Were dinosaurs warm-blooded or cold-blooded? Maybe both.]

Scientists believe that the megalodon’s warmer body allowed it to move faster, tolerate colder water, and spread all over the world’ oceans. However, this evolutionary advantage could have contributed to its downfall. The megalodon lived during the Pliocene Epoch (5.33 million years to 2.58 million years ago) when the world cooled and sea levels changed. These ecosystem changes and competition with newcomers in the marine environment like great whites may have led to its extinction. 

Understanding how extinct sharks met their end could help scientists gauge how today’s warm-blooded sharks could fare due to warmer ocean temperatures from human-caused climate change. It has potential conservation implications and could explain some shifting patterns of where sharks are foraging. 

“We believe changing environments in the deep past was a major contributor to the megalodon’s extinction, as we think it could no longer meet the energetic demands of being a large regional endotherm,” study co-author and Trinity College marine biologist Haley Dolton said in a statement. “We know the seas are warming at alarming rates again now and the smalltooth tiger that washed up in Ireland was the first one seen in these waters. That implies its range has shifted, potentially due to warming waters, so a few alarm bells are ringing.”   

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Reviled the world over for making our scalps itch and rapidly spreading in schools, lice have hitched their destiny to our hair follicles. They are the oldest known parasites that feed on the blood of humans, so learning more about lice can tell us quite a bit about our own species and migratory patterns. 

[Related: Ancient ivory comb shows that self-care is as old as time.]

A study published November 8 in the open-access journal PLOS ONE found that lice likely came into North America in two waves of migration. First when some humans potentially crossed a land bridge that connected Asia with present day Alaska roughly 16,000 years ago during the end of the last ice age and then again during European colonization. 

“In some ways, lice are like living fossils we carry around on our own heads,” study co-author Marina Ascunce, an evolutionary biologist with the United States Department of Agriculture, tells PopSci.  

Lice are wingless parasites that live their entire lives on their host and there are three known species that infest humans. Humans and lice have coevolved for thousands of years. The oldest louse specimen known to scientists is 10,000 years old and was found in Brazil in 2000. Since lice and humans have a very intertwined relationship, studying lice can offer clues into human migratory patterns.

“They went on this ride across the world with us. Yet, they are their own organism with some ability to move around on their own (e.g., from one head to another). It provides insight into what happened during our time together,” study co-author and mammal geneticist from the University of Florida David L. Reed tells PopSci. 

In this new study, a team of scientists from the United States, Mexico, and Argentina analyzed the genetic variation in 274 human lice uncovered from 25 geographic sites around the world. The analysis showed distinct clusters of lice that rarely interbreed and were found in different locations. Cluster I was found all over the world, while Cluster II was found in Europe and the Americas. The only lice that had ancestry from both clusters are found in the Americas. This distinct group of lice appears to be the result of a mixture between lice that were descended from populations that arrived with the people who crossed the Bering Land Bridge into North America and those descended from European lice. 

Researchers found genetic evidence that head lice mirrored both the movement of people into the Americas from Asia and European colonization after Christopher Columbus’s arrival in the late 1400’s.

“Central American head lice harbored the Asian background associated with the foundation of the Americas, while South American lice had marks of the European arrival,” Ariel Toloza, a study co-author and insect toxicologist at Consejo Nacional de Investigaciones Científicas y Técnica (CONICET) in Argentina, tells PopSci. “We also detected a recent human migration from Europe to the Americas after WWII.” 

[Related: Rare parasites found in 200 million-year-old reptile poop.]

The evidence in this study supports the theory that the first people living in the Americas came from Asia between 14,000 and 16,000 years ago and moved south into Central and South America. However, other archaeological evidence like the 23,000 to 21,000 year-old White Sands footprints and Native American tradition suggests that humans were already living in the Americas before and during the last ice age. Some potentially 30,000-year-old stone tools were discovered in a cave in Central Mexico in 2020, which also questions the land bridge theory. 

The study also fills in some of lice’s evolutionary gaps and the team sequenced the louse full genome for future research. 

“The same louse DNA used for this first study was used to analyze their whole genomes and also more lice were collected, so in the next year or so, there will be new studies trying to answer our ongoing questions,” says Ascunce. 

Technological improvements can also now help scientists study include ancient DNA from lice that has been found in mummies or even from louse DNA recovered from ancient combs. The study also offers some lessons in studying animals that we may generally experience as a nuisance.

“The world is full of a lot of plants and animals that are reviled or despised,” says Reed. “You never fully [know] what role they play in the environment or what their true value might be. So, be curious and see what stories the lowliest of animals might have to tell.”

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North Carolina’s Outer Banks saw a busy sea turtle nesting season this year. The barrier islands stretching from Ocracoke Island north to the Virginia state saw 459 total nests between May and October, according to reporting from The Virginian-Pilot and three conservation groups in the state dedicated to sea turtle nesting.

[Related: This waddling robot could guide baby turtles to the sea.]

There are six species of sea turtles native to the United States—green, hawksbill, Kemp’s ridley, leatherback, loggerhead, and olive ridley. All six species are protected by the Endangered Species Act and four of them are known to nest in North Carolina. Human activities are the biggest threats to sea turtle species around the world. The National Oceanic and Atmospheric Administration (NOAA) says that their biggest threats are being caught in fishing gear, nesting and habitat loss, pollution and marine debris, boat strikes, climate change, and the direct harvest of sea turtles and eggs.

During the early to middle of the summer in the Outer Banks, female turtles return to the same beaches where they hatched to dig nests into the sand. They use their back flippers to dig a hole in the ground to deposit the eggs, and then cover it back up with sand. According to the National Park Service, the nesting process takes about one to three hours to complete. 

The tiny turtles hatch a few months later and follow the light of the moon to the ocean. However, their journey from their nests is quite hazardous, as they can be misdirected by artificial lights from homes and streets, crushed by human activity, or eaten by predators on their way to the ocean. 

[Related: Endangered green turtles are bouncing back in the Seychelles.]

At Cape Hatteras National Seashore, this year tied with 2022 as the second-busiest nesting season on record with 379 reported nests. The area covers more than 70 miles and stretches from Ocracoke Island north to Nags Head. The National Park Service says that the first nest was found on May 12 and the most recent was seen on October 29. The nests comprised 324 loggerhead turtles, 51 green turtles, three Kemp’s ridleys, and one leatherback. The leatherback nest was the first one seen on Hatteras National Seashore in 11 years.

Pea Island National Wildlife Refuge on the northern end of Hatteras island reported its third-busiest nesting season since 2009. The refuge covers about 13 miles and saw 43 sea turtle nests this year. By species, 37 nests belonged to loggerhead turtles and six were green turtle nests, according to data from the Sea Turtle Nest Monitoring System.

The nonprofit Network for Endangered Sea Turtles (NEST) also reported its third-busiest nesting season since 2015. Vice President Susan Silbernagel said 30 nests belong to loggerhead turtles and seven were green turtle nests. The all-volunteer organization covers about 50 miles from Nags Head up to Virginia. 

[Related: Safely share the beach with endangered sea turtles this summer.]

To better protect the endangered turtles, volunteers and scientists have been regularly monitoring the region’s beaches since 1997. Staff members and volunteers at Cape Hatteras will establish a buffer zone around the nests for added protection. 

“We could not manage and monitor sea turtle nesting without the help of over 50 dedicated volunteers that assist with monitoring of our nests and reporting and responding to sea turtle strandings,” Michelle Tongue told The Virginian-Pilot. Tongue is the deputy chief of resource management and science for the National Park Service’s Outer Banks Group. 

Sea turtles spend the vast majority of their lives in the ocean and are among the largest reptiles in the world. Kemp’s ridley and green sea turtles weigh about 75 to 100 pounds, while leatherbacks can weigh about 2,000 pounds. Sea turtles are set apart from their pond or land-dwelling relatives by their flippers. Instead of these appendages, land and pond turtles have feet with claws. 

Continued monitoring and vigilance during the 2024 nesting season will hopefully increase survival rates for these endangered reptiles.

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Humans are the only primates currently living in the wild in North America, but that was not always the case. The continent was once home to non-human primates, including big-eyed tarsier-like animals called omomyiforms and long-tailed critters called adapiforms. About 30 million years ago, a lemur-like creature named Ekgmowechashala was the last primate to inhabit the continent before Homo sapiens arrived. In a study published November 6 in the Journal of Human Evolution, fossil teeth and jaws shed some new light on this mysterious creature. 

[Related: 12-million-year-old ape skull bares its fangs in virtual reconstruction.]

From China to Nebraska

Understanding the origins of North America’s primates has been a paleontological puzzle. It’s been unclear whether they evolved on the continent or arrived from somewhere else via land bridges. The first first primates in North America date back about 56 million years at the beginning of the Eocene Epoch. Scientists believe that the primates like Ekgmowechashala generally flourished on the continent for over 20 million years. 

Ekgmowechashala was about five pounds and only one foot tall. They lived in what is now the American Plains just after the Eocene-Oligocene transition. At this time, a huge cooling and dying event made the continent much less hospitable for primates. Ekgmowechashala went extinct about 34 million years ago. 

For the study, paleontologists first had to reconstruct Ekgmowechashala’s family tree with the help of  an older “sister taxon,” or a closely related group of animals. Both groups generally share a branch on their family trees, but diverged at some point and have different lineages. This sister animal originates in and the team named it Palaeohodites, which means “ancient wanderer.” The fossils were collected by paleontologists from the United States in the 1990s from the Nadu Formation in Guangxi, an autonomous region in China. The fossils closely resembled the Ekgmowechashala material that had been found in North America in the 1960s, when the primate was still quite mysterious to North American paleontologists.

The Palaeohodites fossil potentially helps resolve the mystery of Ekgmowechashala’s strange presence in North America. It was likely a migrant to the continent instead of being the product of local evolution.

“Due to its unique morphology and its representation only by dental remains, its place on the mammalian evolutionary tree has been a subject of contention and debate. There’s been a prevailing consensus leaning towards its classification as a primate,” study co-author and University of Kansas PhD candidate Kathleen Rust said in a statement. “But the timing and appearance of this primate in the North American fossil record are quite unusual. It appears suddenly in the fossil record of the Great Plains more than 4 million years after the extinction of all other North American primates, which occurred around 34 million years ago.”

[Related: These primate ancestors were totally chill with a colder climate.]

The Ekgmowechashala fossils found in the US during the 1960s include an upper molar that looks very similar to the Palaeohodites molars found in China, according to study co-author and University of Kansas paleontologist Chris Beard. The team from Kansas closely analyzed the fossils to establish evolutionary relationships between the American Ekgmowechashala and its cousin Palaeohodites. 

The paleontologists believe that Ekgmowechashala did not descend from an older North American primate that survived the climate shift roughly 33 million years ago that caused other North American primates to go extinct. Instead, Ekgmowechashala’s ancestors likely crossed over the icy Beringian region that once connected Asia and North America millions of years later.

Rising from the dead

Ekgmowechashala is an example of the “Lazarus effect” in paleontology. This is where a species suddenly appears in the fossil record long after their relatives have died off. It is a reference to Lazarus who, according to New Testament mythology, was raised from the dead. It is also a pattern of evolution seen in the fossil record of North American primates, who went extinct about 34 million years ago. 

“Several million years later Ekgmowechashala shows up like a drifting gunslinger in a Western movie, only to be a flash in the pan as far as the long trajectory of evolution is concerned,” Beard said in a statement. “After Ekgmowechashala is gone for more than 25 million years, Clovis people come to North America, marking the third chapter of primates on this continent. Like Ekgmowechashala, humans in North America are a prime example of the Lazarus effect.”

The past is prologue?

Studying the way primates were affected by previous changes in climate can provide important insight to today’s human-driven climate change. Organisms generally retreat to more hospitable regions with the available resources or end up going extinct. 

“Around 34 million years ago, all of the primates in North America couldn’t adapt and survive. North America lacked the necessary conditions for survival,” said Rust. “This underscores the significance of accessible resources for our non-human primate relatives during times of drastic climatic change.

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The ability to get lost in thoughts and use our imaginations to daydream might not be completely unique to humans. A study published November 2 in the journal Science found that rats can think about objects and places that are not right in front of them. 

[Related: How science came to rely on the humble lab rat.]

Imagining locations that are away from our current position is a component of both memory and conjuring up possible future scenarios. If animals have this ability, they could have a form of imagination that is similar to our species.

“The rat can indeed activate the representation of places in the environment without going there,” Chongxi Lai, a co-author of the study and engineer and neuroscientist at Howard Hughes Medical Institute, said in a statement. “Even if his physical body is fixed, his spatial thoughts can go to a very remote location.”

To learn more, Lai and a team at Howard Hughes Medical Institute in Maryland designed a series of experiments to see if rats can use their thoughts to imagine going towards a specific location or moving a remote object.

Reading a rat’s mind

When humans and rodents experience events or visit places, specific neural activity patterns are activated in their hippocampus. This area of the brain is responsible for spatial memory and stores mental maps of the rat’s world. It is also involved in recalling past events and imagining future situations. To recall memories, specific patterns related to places and events are generated in the hippocampus. Chimpanzees have been shown to have the ability to pretend, but scientists are still figuring out how chimps and other non-human animals think. 

To peer inside of a rat’s brain and look at these brain patterns, the team developed a real-time “thought detector.” This system measures neural activity and translates what it means using a brain-machine interface (BMI). 

The BMI produced a connection between the electrical activity occurring in the rat’s hippocampus and the animal’s position in a 360-degree virtual reality arena. It allowed the researchers to see if a rat can activate hippocampal activity to think about a location in the virtual arena without physically traveling there. 

A rat ‘thought dictionary’

With the BMI in place, the team worked to decode the brain signals in the rats. They built a “thought dictionary” of what the brain activity patterns looked like when the rat was traveling through the virtual arena in the experiment.

To do this, the rat was harnessed into a virtual reality system. As the rat walked on a spherical treadmill, its movements were translated onto a 360-degree screen. The rat was rewarded when it navigated towards its goal.

While the rat walked on the treadmill, the BMI system recorded the activity occurring in the hippocampus. The team saw which neurons were activated when the rat navigated the virtual arena to reach each goal. These signals provided them with the basis for a real-time translation of what was going on in the hippocampus.

With the thought dictionary set up, the team disconnected the treadmill. The rat was rewarded for the first step of reproducing the hippocampal activity pattern that was associated with walking towards a goal location.

The Jumper task and the Jedi task

Next, they designed two different tasks for the rats to perform–the Jumper task and the Jedi task.

In the Jumper task, the BMI translated the rat’s brain activity into motion on a screen. The animal was essentially using its thoughts to find a reward by thinking about where it needs to go to obtain it. This is a thought process similar to traveling to work or school and imagining the buildings and places we will pass along the way. 

[Related: We probably have big brains because we got lucky.]

The Jedi task had a rat hypothetically move an object to a location in its mind. The rat was fixed in a virtual place, but controlled its hippocampal activity to envision moving the object towards a goal. This is similar to how a person sitting on a couch imagining  getting up and refilling a water glass in a kitchen. The team then changed the location of the rat’s goal, which required it to produce activity patterns associated with the new location.

They found that the rats can precisely and flexibly control their hippocampal activity. Surprisingly, they could sustain this activity and hold their thoughts on a given location for many seconds. This time frame is similar to the amount of time humans can take to relive past events or imagine new scenarios.

“The stunning thing is how rats learn to think about that place, and no other place, for a very long period of time, based on our, perhaps naïve, notion of the attention span of a rat,” Tim Harris, a study co-author and biophysicist from Howard Hughes Medical Institute, said in a statement.

According to the team, this study shows how BMI can be used to probe hippocampal activity and could be a new way to study this critical region of the brain. BMI is increasingly used in prosthetics, and this new work could be used to develop devices based on these same principles.

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Scavenging has been maligned as a food gathering strategy and is generally associated with animals like vultures and hyenas. Millions of years ago, carnivorous dinosaurs may have evolved this technique of taking meat from dead carcasses too. The findings are described in a study published November 1 in the open-access journal PLOS ONE.

[Related: Dinosaur cannibalism was real, and Colorado paleontologists have the bones to prove it.]

Carnivorous dinosaurs like the cannibalistic Allosaurus were surrounded by both living and dead prey. The bodies of large sauropod dinosaurs, some of whom could weigh more than 500,000 pounds, could have provided an important food source for carnivores.

In this study, a team of researchers from Portland State University created a simplified computer simulation of a dinosaur ecosystem from the Jurassic age. They used the animals that have been found in the 163.5 to 145 million year-old Morrison Formation in the western United States as the basis. This enormous fossil formation was once home to a wide variety of plants and dinosaurs.

The model included large carnivores common to the area like Allosaurus, large sauropods and their carcasses, and a large group of living and huntable Stegosaurus’. The carnivores were assigned traits that would improve their hunting abilities with the energy from living meat sources or their scavenging abilities with the sustenance from the carcasses. The model then measured the evolutionary fitness of the simulated predators. 

The model found that when there were a large amount of sauropod carcasses around, scavenging was more profitable than hunting for the Allosaurus. Meat eaters in these kinds of ecosystems may have evolved specialized traits to help them detect and exploit these large carcasses.

“Our evolutionary model demonstrates that large theropods such as Allosaurus could have evolved to subsist on sauropod carrion as their primary resource,” the authors wrote in a statement. “Even when huntable prey was available to them, selection pressure favored the scavengers, while the predators suffered from lower fitness.”

[Related: This 30-pound eagle would take down 400-pound prey and dig through their organs.]

This model represents only a simplified depiction of a complex ecosystem, so more variables like additional dinosaur species may alter the results. While theoretical, using models like this one can help scientists better understand how the availability of meat from carcasses can influence how predators evolve. A September 2023 modeling study found that even early humans living in southern Europe roughly 1.2 to 0.8 million years ago were scavengers. They may have competed in groups of five or more to fight off extinct giant hyenas for the carcasses of animals that had been abandoned by larger predators like saber-toothed cats.

“We think allosaurs probably waited until a bunch of sauropods died in the dry season, feasted on their carcasses, stored the fat in their tails, then waited until the next season to repeat the process,” the authors wrote. “This makes sense logically too, because a single sauropod carcass had enough calories to sustain 25 or so allosaurs for weeks or even months, and sauropods were often the most abundant dinosaurs in the environment.”

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When looking at a sea star–or starfish–it’s not really clear which part of its identical five pointed body is considered its head. This question has puzzled biologists for decades, but some new research says that a starfish’s whole body could function like a head. The findings are described in a study published November 1 in the journal Nature and might have solved the mystery of how sea stars and other echinoderms evolved their distinctively shaped bodies.

[Related: This strange 500-million-year-old sea urchin relative lost its skeleton.]

Searching for heads and trunks 

Sea stars are invertebrates that belong to a group of animals called echinoderms.This group also includes sea urchins and sand dollars and they all have bodies that are arranged in five equal and symmetric sections. Early in their evolution, echinoderms had a bilaterally designed ancestor with two mirrored sides more like a human’s. 

“How the different body parts of the echinoderms relate to those we see in other animal groups has been a mystery to scientists for as long as we’ve been studying them,” Jeff Thompson, a co-author of the study and evolutionary biologist at the University of Southampton in the United Kingdom, said in a statement. “In their bilateral relatives, the body is divided into a head, trunk, and tail. But just looking at a starfish, it’s impossible to see how these sections relate to the bodies of bilateral animals.”

In the new study, an international team of scientists compared the molecular markers in sea stars with a wider group of animals called deuterostomes. This group includes echinoderms like sea star and bilateral animals including vertebrates. Deuterostomes all share a common ancestor, so comparing their development can offer clues into how echinoderms evolved their more unique five-pointed body plan.

They used multiple high-tech molecular and genomic techniques to see where different genes were expressed during a sea star’s development and growth. Micro-CT scanning also allowed the team to understand the shape and structure of the animals in closer detail.

Sea star mapping

Team members from Stanford University, the University of California, Berkeley, and Pacific BioSciences, used techniques called RNA tomography and in situ hybridization to build a three-dimensional map of a sea star’s gene expression to see where specific genes are being expressed during development. They specifically mapped the expression of the genes that control the growth of a sea star’s ectoderm, which includes its nervous system and skin. 

They found gene signatures associated with head development almost everywhere in juvenile sea stars. The expression of genes that code for an animal’s torso and tail sections were also largely missing.

[Related: What’s killing sea stars?]

“When we compared the expression of genes in a starfish to other groups of animals, like vertebrates, it appeared that a crucial part of the body plan was missing,” said Thompson. “The genes that are typically involved in the patterning of the trunk of the animal weren’t expressed in the ectoderm. It seems the whole echinoderm body plan is roughly equivalent to the head in other groups of animals.”

The molecular signatures that are typically associated with the front-most portion of an animal’s head were also localized towards the middle of each of the sea star’s five arms. 

“It’s as if the sea star is completely missing a trunk, and is best described as just a head crawling along the seafloor,” study co-author and Stanford University evolutionary biologist Laurent Formery said in a statement. “It’s not at all what scientists have assumed about these animals.” 

Sea stars and other echinoderms may have evolved their five-section body plan by losing the trunk region that their bilateral ancestors once had. This chance would have allowed them to move around and feed differently than animals with two symmetrical arms.

“Our research tells us the echinoderm body plan evolved in a more complex way than previously thought and there is still much to learn about these intriguing creatures,” said Thompson. “As someone who has studied them for the last ten years, these findings have radically changed how I think about this group of animals.”

This research was supported by the Leverhulme Trust, NASA, the NSF, and the Chan Zuckerberg BioHub.

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As Earth rotates and the sun moves across the sky from east to west, sunflowers turn their brilliant yellow faces to follow it. The mechanics behind this process, called heliotropism, is still a mystery to plant biologists. A study published October 31 in the journal PLOS Biology likely rules out that a sunflower’s ability to follow the sun is related to a more well-known response to light that all plants follow. Sunflowers probably rely on several more complicated processes to track the sun instead. 

[Related: The mathematical theory that connects swimming sperm, zebra stripes, and sunflower seeds.]

Since plants are rooted in one place, they can’t move if light they need to make food is blocked by a neighbor or if they are in a shady spot. They rely on growth or elongation to move towards the light and there are several molecular systems behind this. The best-known response is the phototropic response. Proteins called phototropins sense blue light falling unevenly on a seedling and the plant’s growth hormones are redistributed. This ultimately causes it to bend towards the light.

Plant biologists have long assumed that the sunflower’s ability to follow the sun would be based on the same mechanism as phototropism. To track the sun, the sunflower’s head leans slightly more on the eastern side of its stem. This positions their head towards the direction where the sun rises. It then shifts west as the sun moves across the sky. An earlier study showed that sunflowers have an internal circadian clock that anticipates the sunrise and coordinates the opening of its florets with the time when pollinating insects arrive in the morning. 

To investigate whether this sun-tracking ability is a shru, the team behind the new study used sunflowers grown in a laboratory and others grown outdoors in sunlight. They looked to see which genes were switched on when both sets of plants were exposed to their light sources. The indoor sunflowers grew straight towards their blue light source in the lab and activated the genes associated with phototropin. The flowers that were grown outdoors and swung their heads with the sun had a different pattern of gene expression. These sunflowers also didn’t have any apparent differences in phototropin molecules between one side of the stem and another. 

“We’ve been continually surprised by what we’ve found as we study how sunflowers follow the sun each day,” study co-author and University of California, Davis plant biologist Stacey Harmer said in a statement. “In this paper, we report that they use different molecular pathways to initiate and maintain tracking movements, and that the photoreceptors best known for causing plant bending seem to play a minor role in this remarkable process.”

The team also blocked blue, ultraviolet, red, or far-red light with shade boxes. The blinders didn’t have any effect on the heliotropism response. According to the team, this indicates that there are probably multiple pathways responding to different wavelengths of light to achieve the same goal of following the sun. 

[Related: Dying plants are ‘screaming’ at you.]

The genes involved in heliotropism have not yet been identified. “We seem to have ruled out the phototropin pathway, but we did not find a clear smoking gun,” Harmer said.

When the sunflowers grown in the lab were moved outside, they began to track the sun on their first day. They initially showed a huge burst of gene expression on the shaded side of the plant that did not happen on the following days. Harmer said this suggests some kind of “rewiring” is going on in the plant.

In addition to weeding out some of the process behind how sunflowers track the sun, this work also has relevance for designing future experiments with plants to understand their mechanisms.

“Things that you define in a controlled environment like a growth chamber may not work out in the real world,” Harmer said. 

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Lampreys are the vampires of the ocean and the lakes they can invade. While these eel-like parasitic vertebrates don’t use two sharp fangs to suck blood, lampreys have a toothed oral sucker that latches onto their prey and feasts on their host’s blood. Modern day lampreys are found in temperate zones of most of the world’s oceans except in Africa. However, specimens of their extinct ancient ancestors are fairly rare in the fossil record, despite dating back roughly 360 million years. Now, paleontologists in northern China have found two unusually large fossilized lamprey species that fill a large evolutionary gap. The specimens are described in a study published October 31 in the journal Nature Communications.

[Related: Why sea lampreys are going to be a bigger problem for the Great Lakes.]

“We found the largest fossil lampreys ever found in the world,” study co-author and Chinese Academy of Sciences paleontologist Feixiang Wu tells PopSci. “Based on these fossils, our study assumed that the most recent common ancestor of modern lampreys was likely eating flesh rather than sucking blood as conventionally believed.”

The earliest known lampreys date back about 360 million years ago during the Paleozoic Era. These early species are believed to have been only a few inches long and had weak feeding structures. The 160 million-year-old fossils in this new study were discovered in the Lagerstätte Yanliao Biota in northeastern China and date back to the Jurassic. The longer of the two specimens is named Yanliaomyzon occisor. It is more than 23 inches long and is estimated to have had 16 teeth. The shorter 11 inch-long species is named Yanliaomyzon ingensdentes and had about 23 teeth. By comparison, modern lampreys range from six to 40 inches long.

Their well-preserved oral discs and “biting” structures indicate that these lamprey species had already evolved enhanced feeding structures, bigger body size, and were predators by the Jurassic period. It also appears that they had already evolved a three-phased life cycle by this point

Lampreys begin their lives as burrowing freshwater larvae called ammocetes. During this stage, they have rudimentary eyes and feed on microorganisms with their toothless mouths. They spend several years in this stage, before transforming into adults. Some move into saltwater, while others will remain in freshwater. As adults, they become parasites that attach to a fish with their mouths and feed on their blood and tissue. Lampreys eventually return to freshwater to reproduce, where they build a nest, then spawn, and then die.

It is still unclear when lampreys evolved this lifecycle and their more complex teeth for feeding. These new well-preserved fossils fill an important gap in the fossil record and give some insights into how its lifecycle and feeding originated. 

[Related: Evolution made mosquitos into stealthy, sensitive vampires.]

The study also pinpoints where and when today’s lamprey’s first appeared. “We put modern lampreys’ origin in the Southern Hemisphere of the Late Cretaceous,” says Wu. 

The Late Cretacous lasted from 100.5 million years ago to 66 million years ago and ended with the mass extinction event that wiped out the dinosaurs. In future research, the team would like to search for specimens from the Cretaceous. According to Wu, this time period could be very important to their evolutionary history.

More fossilized specimens could also provide more accurate ideas of what kinds of flesh ancient lampreys feasted on with all those teeth and how that has evolved over time. 

“Living lampreys are always hailed as ‘water vampires,’ but their ancestor might be a flesh eater, their teeth tell,” says Wu. 

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Paleontologists in North Dakota have discovered new species of mosasaur. These giant meat-eating aquatic lizards swam the Earth’s seas about 80 million years ago during the late Cretaceous period. This new species is named Jormungandr walhallaensis after a sea serpent in Norse mythology named Jörmungandr and Walhalla, North Dakota where its fossils were found. The findings are described in a study published October 30 in the Bulletin of the American Museum of Natural History.  

[Related: Dinosaurs who stuck together, survived together.]

“If you put flippers on a Komodo dragon and made it really big, that’s what it would have looked like,” study co-author and Richard Gilder Graduate School PhD student Amelia Zietlow, said in a statement.

The first mosasaur specimens were discovered over 200 years ago and the word “mosasaur” even predates the word “dinosaur” by roughly 20 years. There are still several unanswered questions about these ancient sea lizards, including how many times they evolved to have flippers and when they became fully aquatic. Scientists believe that they evolved to have their signature flippers at least three times and possibly four or more. It is also still a mystery if mosasaurs are more closely related to present day monitor lizards or snakes or another living creature entirely. This new specimen fills in some knowledge gaps of how the different groups of mosasaurs are related to each other.

“As these animals evolved into these giant sea monsters, they were constantly making changes,” Zietlow said. “This work gets us one step closer to understanding how all these different forms are related to one another.”

Researchers in northeastern North Dakota first discovered the Jormungandr fossil in 2015. It included a nearly complete skull, jaws, and cervical spine, and a number of vertebrae. An extensive analysis revealed that the fossil is of a new species that has multiple features that are also seen in two other mosasaurs: Clidastes and Mosasaurus. Clidastes is a smaller animal of about six to 13 feet long that lived roughly 145 million years ago. Mosasaurus was much larger at almost 50 feet long and lived about 99.6 to 66 million years ago alongside the Tyrannosaurus rex. 

[Related: This four-legged snake fossil was probably a skinny lizard.]

The new specimen is about 24 feet long and has flippers. It also has a shark-like tail similar to other early mosasaur species. It also likely would have had “angry eyebrows,” caused by a bony ridge on its skull. Its slightly stumpy tail would have also been shorter than the rest of its body.

Jormungandr was likely a precursor to the bigger Mosasaurus. 

“This fossil is coming from a geologic time in the United States that we don’t really understand,” study co-author and paleontologist from the North Dakota Geological Survey Clint Boyd said in a statement. “The more we can fill in the geographic and temporal timeline, the better we can understand these creatures.”

In Norse mythology, Jörmungandr is an enormous sea serpent or worm who encircles the Earth. Jörmungandr is believed to be the middle child of the trickster god Loki and the giantess Angrboða. Thor the god of thunder also has an ongoing battle with Jörmungandr and it is believed that the two will fight to the death during Ragnarok, or the end of the world. 

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Bats and spiders get most of the attention for Halloween and spooky season, but October is also ladybug time in many parts of the United States. Alongside their appropriately nicknamed cousins the “Halloween beetle,” residents from Wisconsin to North Carolina to New Hampshire historically report seeing more of these insects indoors this time of year. Here’s why.

[Related: These fold-up robots fly just like ladybugs.]

Looking for warmth

Ladybugs typically spend the warmer summer months outside in gardens and grasses. As fall settles in, the insects likely begin to seek a place to hibernate indoors when the temperatures begin to drop. 

They could also be looking for a safe and warm place to lay their eggs. According to This Old House, ladybugs will often leave a trail of pheromones that tells other ladybugs in the colony, “Hey, this place is safe, warm, and perfect for egg-laying,” when they find a good spot to lay eggs. 

They are most commonly spotted by doors and windows, where it is easy for them to squeeze inside under cracks. They can also hitch a ride on potted plants and flowers brought into the home.

How to tell a ladybug from a Halloween beetle

The more well-known and common seven spotted ladybugs (Hippodamia convergens) are often confused with their cousins the Asian lady beetle aka harlequin ladybird or the Halloween beetle (Harmonia axyridis). These bugs are also red, but can also appear more orange and have more spots on their backs. It is also more typical for them to swarm houses in the fall and before the winter. Both species are members of the Coccinellidae family of beetles, but belong to a different genus. 

The easiest way to tell the two cousins apart is to look at their spots. If there are more spots, it’s a Halloween beetle. If there are only seven, it’s a ladybug. You can also look around their “neck.” Halloween beetles have different markings that look a bit like a butterfly or a black “M.” They are also generally larger than ladybugs. 

Ladybugs also typically have a rounded or oval shape. Halloween beetles also have an oval appearance, but they are slightly longer with a pointed head and snout. 

According to University of Kentucky entomologists, Asian lady beetles seem to be attracted to lit up surfaces that have a light-dark surface contrast. Homes that are partially illuminated by the sun are then attractive to the beatles. 

[Related: How many ants are there on Earth? Thousands of billions.]

“Once the beetles alight on buildings, they seek out crevices and protected places to spend the winter. They often congregate in attics, wall cavities, and other protected locations,” the entomologists told WBIR-TV in Knoxville, Tennessee. “Since lady beetles are attracted to light, they are often seen around windows and light fixtures.”

Can they hurt me or my house?

Ladybugs do more good than harm. They do not carry any diseases and they are a garden’s best friend, by eating aphids and worms that can ruin spring flowers and veggies. Halloween beetles are generally more likely to infest a home. 

They are not typically aggressive to humans, but Halloween beetles can bite if they feel trapped or threatened. Like other insects, their bites can create small, red, and itchy marks. 

Halloween beetles can also harm furniture or carpets with their secretions. Some safe ways to keep them away include planting mums, lavender, bay leaves, cloves, citronella, and plants in the citrus and mint families to naturally repel ladybugs, sealing entry points to your home, and using door sweeps at the bottom of doors. 

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Before your most recent meal, you might have felt some hunger pangs, signaling it was time to eat. Maybe you developed a sudden craving for Italian or another cuisine. These cues did not come out of thin air—they are the work of an almond-sized region in the brain called the hypothalamus. This area of the brain, despite its tiny size, has an enormous job in keeping us alive.

Nicknamed the master switchboard, the hypothalamus works in the background making sure our bodies are in the best condition possible. And, like the way many background actors are kept on the edges of a frame, its role has been taken for granted in the science community. “The hypothalamus is a very underappreciated region,” says Dayu Lin, a professor in the department of neuroscience and physiology at the NYU Grossman School of Medicine. She’s seen research interest in the brain region wane, with some even considering it to be less interesting compared to areas involved in higher and complex cognition.

But there’s still much more we have yet to uncover about the hypothalamus, as four review papers show in a series published by the journal Science today. Advanced technology has opened up new ways of examining the small brain region, redefining its old roles and identifying previously unknown ones. 

The body’s regulator

The hypothalamus controls a variety of vital processes. Working with the pituitary gland, it’s in charge of all hormone production. It is also involved in controlling temperature, blood pressure, heart rate, appetite, and other parts of our physiology. 

“The hypothalamus is regarded as an integral element in central nervous system control of both bodily hormonal activity, as well as a number of cognitive, emotional, and behavioral states,” says James Giordano, a Pellegrino Center professor of neurology at Georgetown University Medical Center, who was not involved in the current studies. 

Complex structures and circuits give the hypothalamus a wide range of influence over multiple bodily processes, the first new paper shows. The hypothalamus is divided into a cluster of cell bodies, called nuclei, with intersecting pathways that help it communicate and coordinate activity within itself and with other outside brain regions. “Hypothalamic function is critical to the integrative activity of the brain, and in this way can be seen as important to defining the integrity of body to brain, and brain to body activity,” Giordano adds.

[Related: New human brain atlas is the most detailed one we’ve seen yet]

Until now, a lack of scientific resources prevented researchers from understanding the function of these cells. Lin, who co-authored another paper on the brain region’s role in social behavior, said it was difficult to study what was going on in this area without disrupting the communication between cells. Past research relied on animals with lesions in specific areas of the hypothalamus, but this does not give a full picture of how the removed cells interact with the rest of the region. 

The 2009 invention of single-cell RNA sequencing, a laboratory technique that allows scientists to analyze the genetic information of individual cells, has helped in better dissecting the circuitry that give hypothalamic clusters their diverse functions. In the recent work, researchers have mapped the cell subtypes in the hypothalamus based on. The next challenges will be to figure out why certain cell types group together and how the clumps govern different behaviors.

This isn’t the only new tool that these scientists employed. Another new research technique, optogenetics, allows neuroscientists to use light to monitor brain cell activity. A third, retrograde tracing, uses a virus to track neural connections starting from synapses all the way to their cell bodies, which helped identify never-before-seen circuits. In the future, these could reveal the hypothalamus’s other roles in regulating behaviors that include pain responses and anxiety. At the same time, the study authors speculate that the hypothalamus directly connects to the gut microbiome, with the implication that this brain area would be in charge of gut bacterial effects as well as serotonin and other hormones involved in the regulation of food. 

Sleep, socialization, and goals

The other three papers focus on some of this brain controller’s major functions. Sleep, for example, is governed by specific neurons that act as a “switch” for transition from rest to wakefulness. But that’s not their only purpose. Sleep-wake cells are equally involved with other hypothalamic activities such as the control of energy metabolism and core body temperature.

“Our manuscript highlights the fact that most neuronal circuits in the hypothalamus serve more than one function, and that they are all interconnected,” says Luis de Lecea, a professor of psychiatry and behavioral sciences at Stanford University who served as author of the new review article. “Sleep is [also] intertwined with pretty much all brain function and loss of sleep affects many aspects of our health including aging and neurodegeneration.”

Another review article focused on how the hypothalamus can promote motivation towards necessities for us to survive such as food and water. To aim us toward such goals, the hypothalamus organizes its neural circuits to work with the ventral tegmental area, a part of the brain involved with reward processes. Optogenetic stimulation has revealed the hypothalamus sends messages to the ventral tegmental area that reinforce or inhibit motivation, and could explain food-seeking behavior. 

[Related: Psychedelics and anesthetics cause unexpected chemical reactions in the brain]

It also influences how we interact with others in a range of social behaviors. These can involve friendly and parental interactions, or aggressive or sexual actions. “These behaviors are critical for the animals to survive in the community and reproduce. The hypothalamus is essential for mediating these daily interactions,” says Lin, a co-author of this paper.

In that research, Lin proposes a dual-control system between the hypothalamus and brainstem-spinal cord. When someone spots a person they want to interact with, the hypothalamus engages with the dopamine system—dopamine is important for movements and reward—to maintain social interest and reinforce other socially acceptable actions. The brainstem-spinal cord circuit then takes this information and uses it to guide socially favorable responses and actions.

From lab animals to human health

Much of the work in investigating the ins and outs of the hypothalamus are in animals. Transgenic mice—genetically manipulated animals used to study biological processes and human diseases—make it easier for scientists to examine a specific section of the hypothalamus, Lin says, without putting any creatures under anesthesia. This is especially helpful to study communal behaviors, because animals need to be freely moving for their social brain circuits to activate. 

Although these studies originated in animals, the new information about the hypothalamus is already being used to form treatments for humans. Efforts are underway to use deep-brain stimulation to target the posterior end of the hypothalamus to prevent or reduce aggression, for example. There is also potential in targeting specific circuits in the hypothalamus to stop other problems such as insomnia and addiction. In the next 10 years, Lin predicts, we’ll be hearing more news of clinical trials that target the hypothalamus to treat troubling behaviors.

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Living long lives past reproductive age is a real rarity for female members of the animal kingdom. Humans and some species of toothed whales are the only known animals to go through menopause and the reasons behind it are an evolutionary puzzle. A team of primatologists recently found that a group of wild chimpanzees in Uganda also show signs of menopause. The findings are described in a study published October 26 in the journal Science and could provide more insight into this rare biological phenomenon.

[Related: Adolescent chimpanzees might be less impulsive than human teens.]

In humans, menopause typically occurs between the ages of 45 and 55 and is characterized by a natural decline in reproductive hormones and the end of ovarian functions. Some symptoms in humans include chills, hot flashes, weight gain, and thinning hair. The evolutionary benefits of this process are still a mystery for biologists. It is also still unclear why menopause evolved in humans but not in other known long-lived primates. 

“During our ongoing twenty five year study of chimpanzees at Ngogo in Kibale National Park, Uganda, we noticed that many old females did not reproduce for decades,” study co-author and Arizona State University primatologist Kevin Langergraber tells PopSci. “It’s a surprising trait from the perspective of evolution: how and why can natural selection favor the extension of lifespan past the point at which individuals can no longer reproduce? We need to know in what species it occurs and which it doesn’t as a first step [to that question].”

To look closer, the authors calculated a metric called the post-reproductive representation (PrR). This measurement is the average proportion of adult lifespan that an animal spends in its post-reproductive state. Most mammals have a PrR close to zero, but the team found that Ngogo chimpanzees have a PrR of 0.2. This means that the female chimpanzees in this group live 20 percent of their adult years in a post-reproductive state. 

Urine samples from 66 female chimpanzees from different stages in their reproductive lives also showed that the transition to this post-reproductive state was marked by changes in hormones like gonadotropins, estrogens, and progestins. 

While similar hormonal variations are also a way to tell that this transition is happening in humans, the post-reproductive chimpanzees were not involved in raising their offspring’s children. In these chimpanzees, the common grandmother hypothesis, where females live longer after menopause to help take care of future generations, does not appear to apply. This contrasts with some populations of orca whales, where grandmothers are a critical part of raising their offspring’s young to ensure their survival. 

[Related: Nice chimps finish last—so why aren’t all of them mean?]

According to the team, there are two possible explanations for these longer post-reproductive lifespans. Chimpanzees and other mammals in captivity can have artificially long post-reproductive lifespans because they are protected from natural predators and some pathogens. Even though they’re a wild population, the Ngogo chimpanzees could also be similarly protected and live artificially long lives. They live in a relatively remote area that is undisturbed by logging and hunting by humans and are exposed to fewer human pathogens. Their current habitat could also be closer to what existed in their evolutionary past compared with other populations of primates that are more affected by humans.

“The study both illuminates and raises questions about the evolution of menopause,” University of Exeter evolutionary biologist Michael Cant wrote in a related review on the study. “It also highlights the power of difficult long-term field studies–often run on small budgets and at constant risk of closure–to transform fundamental understanding of human biology and behavior.” Cant is not an author of the study.

Langergraber says future studies like this one could answer the question of how common substantial post-reproductive lifespans have been throughout chimpanzee evolutionary history and if impacts from humans have kept their survivorship rates artificially low.

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When foraging, bumblebees often have a choice to make. Do they go for the nectar that is the easiest to get, or should they work harder to get nectar with a higher sugar content? A new study found that the priority for the bumblebees is getting the most calories in the shortest amount of time, even at the expense of using up more energy. This trade-off ensures an immediate energy boost for the bumblebee colony, according to a study published October 24 in the journal iScience.

[Related: Female honeybees may pass down ‘altruistic’ genes.]

The study looked at a common species in the United Kingdom called Bombus terrestris or the buff-tailed bumblebee. Bumblebees will drink nectar from flowers and regurgitate it into their nest for other bees to use. They only store a small amount of nectar in their nests, so they must make the most of every opportunity to forage. 

To make these choices, bumblebees appear to trade off the time that they spend collecting nectar with the energy content of that nectar. If the sugar content is worth it, the bees will work to collect it despite being more difficult to access. By comparison, honeybees make their foraging decisions by optimizing the amount of energy they are expelling for any nectar, likely to prolong a honeybee’s working life.  

“Bumblebees can make decisions ‘on the fly’ about which nectar sources are the most energetically economical,” study co-author and University of Oxford bee biologist Jonathan Pattrick said in a statement. “By training bumblebees to visit artificial slippery flowers and using different ‘nectars’ with high, medium or low amounts of sugar, we found that they could make a trade-off between the energy content of the nectar and how difficult it was to access.”

For the study, Patrick and a team of biologists made 60,000 observations of the bumblebee’s behavior over six months. This allowed them to precisely estimate bumblebee foraging energetics and each bumblebee in the study was observed for up to eight hours a day without a break. The team used artificial flowers that were positioned vertically and horizontally and had slippery surfaces that made it difficult for the bees to grip. 

A computer program measured the split-second timing as the bees flew between the fake flowers and foraged for nectar to see how much energy the bumblebees spent flying and how much they collected while drinking. They then identified how the bees decided whether to spend extra time and energy collecting high-sugar nectar from the slippery flowers, or take the easier option of collecting lower-sugar nectar from flowers they could land on.

Each bumblebee was then given one of three tests.

In test one, the nectar on both the vertical and horizontal artificial flowers contained the same amount of sugar. The bumblebees chose to forage from the horizontal flowers instead of spending the extra time and energy hovering around the vertical flowers.

In test two, the vertical flowers had much more sugary nectar than the horizontal flowers and the bumblebees chose to drink almost exclusively from the vertical flowers.

[Related: Bee brains could teach robots to make split-second decisions.]

In test three, the vertical flowers had slightly more sugary nectar than the horizontal flowers. This created a situation where the bumblebees had to make a tradeoff between the time and energy they spent foraging and the energy content in the nectar they were drinking. They ended up feeding from the horizontal flowers.

Based on these test results, the authors conclude that the bumblebees can choose to spend additional time and energy foraging from the more hard-to-access nectar sources, but only if the eventual reward is really worth it. Understanding how this works can help make predictions about what types of flowers the bumblebees are likely to visit and inform choices of the kinds of flowers planted to make fields more bumblebee friendly.

“It’s amazing that even with a brain smaller than a sesame seed, bumblebees can make such complex decisions,” study co-author and University of Cambridge biochemist Hamish Symington said in a statement. “It’s clear that bumblebee foraging isn’t based on a simple idea that ‘the more sugar there is in nectar, the better’ – it’s much more subtle than that. And it highlights that there’s still so much to learn about insect behavior.”

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With its 19 feet-long torpedo-shaped body and long teeth the newly-described Lorrainosaurus was a fearsome mega predator. The fossilized remains of a 170-million-year-old marine reptile is the oldest-known pliosaur and dates back to the Jurassic era. The discovery is described in a study published October 16 in the journal Scientific Reports.

[Related: Millions of years ago, marine reptiles may have used Nevada as a birthing ground.]

Pliosaurs were members of a group of ocean-dwelling reptiles that are closely related to the more famous long-necked plesiosaurs. Unlike their cousins, these pliosaurs had short necks and massive skulls. From snout to tail, it was likely about 19 feet long and very little is known about the plesiosaurs from this time.

“Famous examples, such as Pliosaurus and Kronosaurus–some of the world’s largest pliosaurs–were absolutely enormous with body-lengths exceeding 10m [32 feet]. They were ecological equivalents of today’s killer whales and would have eaten a range of prey including squid-like cephalopods, large fish and other marine reptiles. These have all been found as preserved gut contents,” study co-author and Uppsala University paleontologist Benjamin Kear said in a statement.

Pliosaurs first emerged over 200 million years ago and remained relatively small players in marine ecosystems. Following a landmark restructuring of the marine predator ecosystem in the early to middle Jurassic era (about 175 to 171 million years ago) they reached apex predator status.

“This event profoundly affected many marine reptile groups and brought mega predatory pliosaurids to dominance over ‘fish-like’ ichthyosaurs, ancient marine crocodile relatives, and other large-bodied predatory plesiosaurs,” study co-author and paleobiologist at the Institute of Paleobiology of the Polish Academy of Sciences Daniel Madzia said in a statement.

The fossils in this study were originally found in 1983 in northeastern France, but were recently analyzed by an international team of paleontologists who identified this new pliosaur genus called Lorrainosaurus. The teeth and bones represent what was once a complete skeleton that decomposed and was spread along the ancient seafloor by scavengers and ocean currents. 

[Related: The planet’s first filter feeder could be this extinct marine reptile.]

“Lorrainosaurus was one of the first truly huge pliosaurs. It gave rise to a dynasty of marine reptile mega-predators that ruled the oceans for around 80 million years,” Sven Sachs, a study co-author and paleontologist from the Naturkunde-Museum Bielefeld in Germany, said in a statement.

Other than a short report published in 1994, these fossils remained obscure until the team reevaluated the specimens. Finding Lorrainosaurus’ remains indicates that the reign of gigantic mega-predatory pliosaurs likely began earlier than paleontologists previously thought. These giants were also locally responsive to the major ecological changes in the marine environments that covered present day Europe during the early Middle Jurassic.

“Lorrainosaurus is thus a critical addition to our knowledge of ancient marine reptiles from a time in the Age of Dinosaurs that has as yet been incompletely understood,” said Kear.

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A group of paleontologists, park rangers, and geologists have discovered a new species of ancient shark in the rock layers of Mammoth Cave National Park in Kentucky. It was uncovered in a large fossil deposit that includes at least 40 different species of shark and their relatives, and even well-preserved skeletal cartilage. 

[Related: Megalodons were likely warm-blooded, despite being stone-cold killers.]

The new species is named Strigilodus tollesonae and is a petalodont shark. These extinct  sharks had petal-shaped teeth and lived about 337 million years ago. According to the National Park Service, it is more closely related to present day ratfish than sharks or rays and it was identified from teeth found in the cave’s walls. Strigilodus tollesonae likely had teeth that included one rounded cusp used for clipping and a long, ridge inert side that crushed prey the way molars do. Paleontologists believe that it likely lived like modern day skates and fed on worms, bivalves, and small fish. 

Strigilodus tollesonae translates to “Tolleson’s Scraper Tooth” and it is named after Mammoth Cave National park guide Kelli Tolleson for her work in the paleontological study that uncovered the new species. 

The limestone caves that make up the 400-mile long Mammoth Cave System were formed about 325-million-years ago during the Late Paleozoic. Geologists call this time period the Mississippian Period, when shallow seas covered much of North America including where Mammoth Cave is today. 

In 2019, the park began a major paleontological resources inventory to identify the numerous types of fossils associated with the rock layers. Mammoth Cave park staff reported a few fossil shark teeth that were exposed in the cave walls of Ste. Genevieve Limestone in several locations. Shark fossils can be difficult to come by, since shark skeletons are made of cartilage instead of bone. Cartilage is not as tough as bone, so it is generally not well-preserved in the fossil record. 

The team then brought in shark fossil specialist John-Paul Hodnett of the Maryland-National Capital Parks and Planning Commission to help identify the shark fossils. Hodnett and park rangers discovered and identified multiple different species of primitive sharks from the shark teeth and fine spine specimens in the rocks lining the cave passages.

“I am absolutely amazed at the diversity of sharks we see while exploring the passages that make up Mammoth Cave,” Hodnett said in a statement. “We can hardly move more than a couple of feet as another tooth or spine is spotted in the cave ceiling or wall. We are seeing a range of different species of chondrichthyans [cartilaginous fish] that fill a variety of ecological niches, from large predators to tiny little sharks that lived amongst the crinoid [sea lily] forest on the seafloor that was their habitat.”

[Related: This whale fossil could reveal evidence of a 15-million-year-old megalodon attack.]

In addition to Strigilodus tollesonae, the team have identified more than 40 different species of sharks and their relatives from Mammoth Cave specimens in the past 10 months. There appear to be at least six fossil shark species that are new to science. According to the team, those species will be described and named in an upcoming scientific publication.

The majority of the shark fossils have been discovered in areas of the park that are inaccessible to the public, so photographs, illustrations, and three-dimensional models have been made to display the discovery. The park also plans to celebrate the new shark fossils with multiple presentations and exhibits on Monday October 23. 

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Honeybees are a model of teamwork in nature, with their complex society and hives that generate enough energy to create an electrical charge. They also appear to be some of the rare animals that display a unique trait of altruism, which is genetically inherited. The findings were described in a study published September 25 in the journal Molecular Ecology.

[Related: Bee brains could teach robots to make split-second decisions.]

Giving it all for the queen bee

According to the American Psychological Association, humans display altruism through behaviors that benefit another individual at a cost to oneself. Some psychologists consider it a uniquely human trait and studying it in animals requires a different framework for understanding. Animals experience a different level of cognition, so what drives humans to be altruistic might be different than what influences animals like honeybees to act in ways that appear to be altruistic.

In this new study, the researchers first looked at the genetics behind retinue behavior in worker honeybees. Retinue behavior is the actions of worker bees taking care of the queen, like feeding or grooming her. It’s believed to be triggered by specific pheromones and worker bees are always female. 

After the worker bees are exposed to the queen’s mandibular pheromone (QMP), they deactivate their own ovaries. They then help spread the QMP around to the other worker bees and they only take care of the eggs that the queen bee produces. Entomologists consider this behavior ‘altruistic’ because it benefits the queen’s ability to produce offspring, while the worker bees remain sterile. 

The queen is also typically the mother of all or mostly all of the honeybees in the hive. The genes that make worker bees more receptive to the queen’s pheromone and retinue behavior can be passed down from either female or male parent. However, the genes only result in altruistic behavior when they are passed down from the female bee parent.

“People often think about different phenotypes being the result of differences in gene sequences or the environment. But what this study shows is it’s not just differences in the gene itself—it’s which parent the gene is inherited from,” study co-author and Penn State University doctoral candidate Sean Bresnahan said in a statement. “By the very nature of the insect getting the gene from its mom, regardless of what the gene sequence is, it’s possibly going to behave differently than the copy of the gene from the dad.”

A battle of genetics 

The study supports a theory called the Kinship Theory of Intragenomic Conflict. It suggests that a mothers’ and fathers’ genes are in a conflict over what behaviors to support and not support. Previous studies have shown that genes from males can support selfish behavior in mammals, plants, and honeybees. This new study is the first known research that shows females can pass altruistic behavior onto their offspring in their genes. 

[Really: What busy bees’ brains can teach us about human evolution.]

Worker bees generally have the same mother but different fathers, since the queen mates with multiple male bees. This means that the worker bees share more of their mother’s genes with each other. 

“This is why the Kinship Theory of Intragenomic Conflict predicts that genes inherited from the mother will support altruistic behavior in honeybees,” Breshnahan said. “A worker bee benefits more from helping, rather than competing with, her mother and sisters—who carry more copies of the worker’s genes than she could ever reproduce on her own. In contrast, in species where the female mates only once, it is instead the father’s genes that are predicted to support altruistic behavior.”

Pinpointing conflict networks

To look closer, the team crossbred six different lineages of honeybees. Bresnahan says that this is relatively easy to do in mammals or plants, but more difficult in insects. They used honeybee breeding expertise from co-author Juliana Rangel from Texas A&M University and Robyn Underwood at Penn State Extension to create these populations.

Once the bee populations were successfully crossed and the offspring were old enough, the team assessed the worker bees’ responsiveness to the pheromone that triggers the retinue behavior. 

“So, we could develop personalized genomes for the parents, and then map back the workers’ gene expression to each parent and find out which parent’s copy of that gene is being expressed,” Bresnahan said.

The team identified the gene regulatory networks that have this intragenomic conflict, finding that more genes that have a parental bias were expressed. These networks consisted of genes that previous research showed were related to the retinue behavior.

“Observing intragenomic conflict is very difficult, and so there are very few studies examining the role it plays in creating variation in behavior and other traits,” study co-author and Penn State entomologist Christina Grozinger said in a statement. “The fact that this is the third behavior where we have found evidence that intragenomic conflict contributes to variation in honeybees suggests that intragenomic conflict might shape many types of traits in bees and other species.”

The team hopes that this research will help provide a blueprint for more studies into intragenomic conflict in other animals and plants.

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For nearly half a century, Nikon’s Small World Photomicrography Competition has celebrated the beauty captured by extreme magnification. This year, the photomicrography contest was stacked: a panel of journalists and scientists selected winners from 1,900 entries submitted by researchers and photographers in 72 countries. Subjects as diverse as mutant fish, chemical reactions, and a speck of space rock became works of art when seen really, really up close.

Above, in first place, is a rodent’s optic nerve head. Blood vessels, each only 110 microns in diameter, radiate outward like the fizzing arms of a firework. The yellow star-like shapes surrounding the vessels are astrocytes, cellular helpers that maintain neuronal systems. Vision researchers at the Lions Eye Institute in Perth, Australia—Hassanain Qambari, assisted by Jayden Dickson—imaged the optic disc at 20x magnification as part of a study of diabetic retinopathy; this condition can cause blindness in people with diabetes.

“The visual system is a complex and highly specialized organ, with even relatively minor perturbations to the retinal circulation able to cause devastating vision loss,” Qambari said in a news release. “I entered the competition as a way to showcase the complexity of retinal microcirculation.” Below are other top photos, and you can see even more at Nikon’s Small World site.

[Related: 15 remarkable JWST images that reveal the wonders of our vast universe]

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A team of scientists from Spain and the United States reconstructed the skull of an extinct great ape species from a set of well-preserved, but damaged skeletal remains. The bones belonged to Pierolapithecus catalaunicus who lived roughly 12 million years ago. Studying its facial features could help us better understand human and ape evolution and the findings are described in a study published October 16 in the journal Proceedings of the National Academy of Sciences (PNAS).

[Related: This 7th-century teen was buried with serious bling—and we now know what she may have looked like.]

First described in 2004, Pierolapithecus was a member of a diverse group of extinct ape species that lived during the Miocene Epoch (about 15 to 7 million years ago) in Europe. During this time, horses were beginning to evolve in North America and the first dogs and bears also began to appear. The Miocene was also a critical time period for primate evolution.

In the study, the team used CT scans to virtually reconstruct Pierolapithecus’ cranium. They then used a process called principal components analysis and compared their digital reconstruction of the face with other primate species. They then modeled the changes occurring to some key features of ape facial structure. They found that Pierolapithecus shares similarities in its overall face shape and size with fossilized and living great apes. 

However, it also has distinct facial features that have not been found in other apes from the Middle Miocene. According to the authors, these results are consistent with the idea that Pierolapithecus represents one of the earliest members of the great ape and human family. 

“An interesting output of the evolutionary modeling in the study is that the cranium of Pierolapithecus is closer in shape and size to the ancestor from which living great apes and humans evolved,” study co-author and AMNH paleoanthropologist Sergio Almécija said in a statement. “On the other hand, gibbons and siamangs (the ‘lesser apes’) seem to be secondarily derived in relation to size reduction.”

Studying the physiology of extinct animals like Pierolapithecus can help us understand how other species evolved. This particular primate species is important because the team used a cranium and partial skeleton that belonged to the same individual ape, which is a rarity in the fossil record. 

[Related: Our tree-climbing ancestors evolved our abilities to throw far and reach high.]

“Features of the skull and teeth are extremely important in resolving the evolutionary relationships of fossil species, and when we find this material in association with bones of the rest of the skeleton, it gives us the opportunity to not only accurately place the species on the hominid family tree, but also to learn more about the biology of the animal in terms of, for example, how it was moving around its environment,” study co-author Kelsey Pugh said in a statement. Pugh is a primate palaeontologist with the American Museum of Natural History (AMNH) in New York and Brooklyn College.

Earlier studies on Pierolapithecus suggest that it could have stood upright and had multiple adaptations that allowed these hominids to hang from tree branches and move throughout them. However, Pierolapithecus’ evolutionary position is still debated, partially due to the damage to the specimen’s cranium.  

“One of the persistent issues in studies of ape and human evolution is that the fossil record is fragmentary, and many specimens are incompletely preserved and distorted,” study-coauthor and AMNH biological anthropologist Ashley Hammond said in a statement. “This makes it difficult to reach a consensus on the evolutionary relationships of key fossil apes that are essential to understanding ape and human evolution.”

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This article was originally featured on Hakai Magazine, an online publication about science and society in coastal ecosystems. Read more stories like this at hakaimagazine.com.

In the late 19th century, whalers, settlers, and pirates changed the ecology of the Galapagos Islands by poaching some native species—like Galapagos giant tortoises—and introducing others, like goats and rats. The latter species became pests and severely destabilized the island ecosystems. Goats overgrazed the fruits and plants the tortoises ate while rats preyed on their eggs. Over time, the tortoise population plummeted. On Española, an island in the southeast of the archipelago, the tortoise count fell from over 10,000 to just 14. Along the way, with goats eating all the plants they could, Española—once akin to a savanna—turned barren.

A century later, conservationists set out to restore the Galapagos giant tortoise on Española—and the island ecosystem. They began eradicating the introduced species and capturing Española’s remaining tortoises and breeding them in captivity. With the goats wiped out and the tortoises in cages, the ecosystem transformed once again. This time, the overgrazed terrain became overgrown with densely packed trees and woody bushes. Española’s full recovery to its savanna-like state would have to wait for the tortoises’ return.

From the time those 14 tortoises were taken into captivity between 1963 and 1974 until they were finally released in 2020, conservationists with the NGO Galápagos Conservancy and the Galapagos National Park Directorate reintroduced nearly 2,000 captive-bred Galapagos giant tortoises to Española. Since then, the tortoises have continued to breed in the wild, causing the population to blossom to an estimated 3,000. They’ve also seen the ecology of Española transform once more as the tortoises are reducing the extent of woody plants, expanding the grasslands, and spreading the seeds of a key species.

Not only that, but the tortoises’ return has also helped the critically endangered waved albatross—a species that breeds exclusively on Española. During the island’s woody era, Maud Quinzin, a conservation geneticist who has previously worked with Galapagos tortoises, says that people had to repeatedly clear the areas the seabirds use as runways to take off and land. Now, if the landing strips are getting overgrown, they’ll move tortoises into the area to take care of it for them.

The secret to this success is that—much like beavers, brown bears, and elephants—giant tortoises are ecological architects. As they browse, poop, and plod about, they alter the landscape. They trample young trees and bushes before they can grow big enough to block the albatrosses’ way. The giant tortoises likewise have a potent impact on the giant species of prickly pear cactuses that call Española home—one of the tortoises’ favorite foods and an essential resource for the island’s other inhabitants.

When the tortoises graze the cactus’s fallen leaves, they prevent the paddle-shaped pads from taking root and competing with their parents. And, after they eat the cactus’s fruit, they drop the seeds across the island in balls of dung that offer a protective shell of fertilizer.

The extent of these and other ecological effects of the tortoise are documented in a new study by James Gibbs, a conservation scientist and the president of the Galápagos Conservancy, and Washington Tapia Aguilera, the director of the giant tortoise restoration program at the Galápagos Conservancy.

To study these impacts up close, they fenced off some of the island’s cactuses, which gave them a way to assess how the landscapes evolve when they’re either exposed to or free from the tortoises’ influences. They also studied satellite imagery of the island captured between 2006 and 2020 and found that while parts of the island are still seeing an increase in the density of bushes and trees, places where the tortoises have rebounded are more open and savanna-like.

As few as one or two tortoises per hectare, the scientists write, is enough to trigger a shift in the landscape.

Dennis Hansen, a conservation ecologist who has worked with the tortoises native to the Aldabra atoll in the Indian Ocean, says that while the findings line up with what conservationists expected, it was nice to have their suspicions confirmed. The results bode well for other rewilding projects that include giant tortoise restoration as a keystone of their efforts, he says, such as those underway on other islands in the Galapagos archipelago and on the Mascarene Islands in the Indian Ocean.

But on Española itself, though the tortoises have been busy stomping shoots and spreading seeds, they have more work to do. In 2020, 78 percent of Española was still dominated by woody vegetation. Gibbs says it may take another couple of centuries for Española’s giant tortoises to reestablish something like the ratio of grasses, trees, and bushes that existed before Europeans landed in the archipelago. But that long transformation is at least underway.

This article first appeared in Hakai Magazine and is republished here with permission.

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This article originally appeared in Knowable Magazine.

Back at the turn of the 21st century, Valley fever was an obscure fungal disease in the United States, with fewer than 3,000 reported cases per year, mostly in California and Arizona. Two decades later, cases of Valley fever are exploding, increasing more than sevenfold and expanding to other states.

And Valley fever isn’t alone. Fungal diseases in general are appearing in places they have never been seen before, and previously harmless or mildly harmful fungi are turning deadly for people. One likely reason for this worsening fungal situation, scientists say, is climate change. Shifts in temperature and rainfall patterns are expanding where disease-causing fungi occur; climate-triggered calamities can help fungi disperse and reach more people; and warmer temperatures create opportunities for fungi to evolve into more dangerous agents of disease.

For a long time, fungi have been a neglected group of pathogens. By the early 2000s, researchers were already warning that climate change would make bacterial, viral and parasite-caused infectious diseases like cholera, dengue and malaria more widespread. “But people were not focused at all on the fungi,” says Arturo Casadevall, a microbiologist and immunologist at the Johns Hopkins Bloomberg School of Public Health. That’s because, until recently, fungi haven’t troubled humans much.

Our high body temperature helps explain why. Many fungi grow best at around 12 to 30 degrees Celsius (roughly 54 to 86 degrees Fahrenheit). So, while they find it easy to infect trees, crops, amphibians, fish, reptiles and insects — organisms that do not maintain consistently high internal body temperatures — fungi usually don’t thrive inside the warm bodies of mammals, Casadevall wrote in an overview of immunity to invasive fungal diseases in the 2022 Annual Review of Immunology. Among the few fungi that do infect humans, some dangerous ones, such as species of Cryptococcus, Penicillium and Aspergillus, have historically been reported more in tropical and subtropical regions than in cooler ones. This, too, suggests that climate may limit their reach.

Fungi on the move

Today, however, the planet’s warming climate may be helping some fungal pathogens spread to new areas. Take Valley fever, for instance. The disease can cause flu-like symptoms in people who breathe in the microscopic spores of the fungus Coccidioides. The climatic conditions favoring Valley fever may occur in 217 counties of 12 US states today, according to a recent study by Morgan Gorris, an Earth system scientist at the Los Alamos National Laboratory in New Mexico.

But when Gorris modeled where the fungi could live in the future, the results were sobering. By 2100, in a scenario where greenhouse gas emissions continue unabated, rising temperatures would allow Coccidioides to spread northward to 476 counties in 17 states. What was once thought to be a disease mostly restricted to the southwestern US could expand as far as the US-Canadian border in response to climate change, Gorris says. That was a real “wow moment,” she adds, because that would put millions more people at risk.

Some other fungal diseases of humans are also on the move, such as histoplasmosis and blastomycosis. Both, like Valley fever, are increasingly seen outside what was thought to be their historical range.

Such range extensions have also appeared in fungal pathogens of other species. The chytrid fungus that has contributed to declines in hundreds of amphibian species, for example, grows well at environmental temperatures between 17 and 25 degrees Celsius (63 to 77 degrees Fahrenheit). But the fungus is becoming an increasing problem at higher altitudes and latitudes, likely because rising temperatures are making previously cold regions more welcoming for the chytrid. Similarly, white pine blister rust, a fungus that has devastated some species of white pines across Europe and North America, is expanding to higher elevations where conditions were previously unfavorable. This has put more pine forests at risk. Changing climatic conditions are also helping drive fungal pathogens of crops, like those infecting bananas, potatoes and wheat, to new areas.

A warming climate also changes cycles of droughts and intense rains, which can increase the risk of fungal diseases in humans. One study of more than 81,000 cases of Valley fever in California between 2000 and 2020 found that infections tended to surge in the two years immediately following prolonged droughts. Scientists don’t yet fully understand why this happens. But one hypothesis suggests that Coccidioides survives better than its microbial competitors during long droughts, then grows quickly once rains return and releases spores into the air when the soil begins to dry again. “So climate is not only going to affect where it is, but how many cases we have from year to year,” says Gorris.

By triggering more intense and frequent storms and fires, climate change can also help fungal spores spread over longer distances. Doctors have observed unusually large outbreaks of Valley fever just after dust storms or other events that kick up clouds of dust. Similarly, researchers have found a surge in Valley fever infections in California hospitals after large wildfires as far as 200 miles away. Scientists have seen this phenomenon in other species too: Dust storms originating in Africa have been implicated in moving a coral-killing soil fungus to the Caribbean.

Researchers are now sampling the air in dust storms and wildfires to see if these events can actually carry viable, disease-causing fungi for long distances and bring them to people, causing infections. Understanding such dispersal is key to figuring out how diseases spread, says Bala Chaudhary, a fungal ecologist at Dartmouth College who coauthored an overview of fungal dispersal in the 2022 Annual Review of Ecology, Evolution, and Systematics. But there’s a long road ahead: Scientists still don’t have answers to several basic questions, such as where various pathogenic fungi live in the environment or the exact triggers that liberate fungal spores out of soil and transport them over long distances to become established in new places.

Evolving heat tolerance

Helping existing fungal diseases reach newer places isn’t the only effect of climate change. Warming temperatures can also help previously innocuous fungi evolve tolerance for heat and become deadlier. Researchers have long known that fungi are capable of this. In 2009, for example, researchers showed that a fungus — in this case a pathogen that infects hundreds of insect pests — could evolve to grow at 37 degrees Celsius, five degrees higher than its previous upper thermal limit, after just four months. More recently, researchers grew a dangerous human pathogen, Cryptococcus deneoformans, at both 37 degrees Celsius (similar to human body temperature) and 30 degrees Celsius in the lab. The higher temperature triggered a fivefold rise in mutations in the fungus’s DNA compared to the lower temperature. Rising global temperatures, the researchers speculate, could thus help some fungi rapidly adapt, increasing their ability to infect people.

There are examples from the real world too. Before 2000, the stripe rust fungus, which devastates wheat crops, was restricted to cool, wet parts of the world. But since 2000, certain strains of the fungus have become better adapted to higher temperatures. These sturdier strains have been replacing the older strains and spreading to new regions.

This is worrying, says Casadevall, especially with hotter days and heatwaves becoming more frequent and intense. “Microbes really have two choices: adapt or die,” he says. “Most of them have some capacity to adapt.” As climate change increases the number of hot days, evolution will select more strongly for heat-resistant fungi.

And as fungi in the environment adapt to tolerate heat, some might even become capable of breaching the human temperature barrier.

This may have happened already. In 2009, doctors in Japan isolated an unknown fungus from the ear discharge of a 70-year-old woman. This new-to-medicine fungus, which was given the name Candida auris, soon spread to hospitals around the world, causing life-threatening bloodstream infections in already sick patients. The World Health Organization now lists Candida auris among its most dangerous group of fungal pathogens, partly because the fungus is showing increasing resistance to common antifungal drugs.

“In the case of India, it’s really a nightmare,” says Arunaloke Chakrabarti, a medical mycologist at the Postgraduate Institute of Medical Education and Research in Chandigarh, India. When C. auris was first reported in India more than a decade ago, it was low on the list of Candida species threatening patients, Chakrabarti says, but now, it’s the leading cause of Candida infections. In the US, cases rose sharply from 63 between 2013 and 2016 to more than 2,300 in 2022.

Where did C. auris come from so suddenly? The fungus appeared simultaneously across three different continents. Each continent’s version of the fungus was genetically distinct, suggesting that it emerged independently on each continent. “It’s not like somebody took a plane and carried them,” says Casadevall. “The isolates are not related.”

Since all continents are exposed to the effects of climate change, Casadevall and his colleagues think that human-induced global warming may have played a role. C. auris may always have existed somewhere in the environment — potentially in wetlands, where researchers have recovered other pathogenic species of Candida. Climate change, they argued in 2019, may have exposed the fungus to hotter conditions over and over again, allowing some strains to become heat-tolerant enough to infect people.

Subsequently, scientists from India and Canada found C. auris in nature for the first time, in the Andaman Islands in the Bay of Bengal. This “wild” version of C. auris grew much slower at human body temperature than did the hospital versions. “What that suggests to me is that this stuff is all over the environment and some of the isolates are adapting faster than others,” says Casadevall.

Like other explanations for C. auris’s origin, Casadevall’s is only a hypothesis, says Chakrabarti, and still needs to be proved.

One way to establish the climate change link, Casadevall says, would be to review old soil samples and see if they have C. auris in them. If the older versions of the fungus don’t grow well at higher temperatures, but over time they start to, that would be good evidence that they’re adapting to heat.

In any case, the possibility of warmer temperatures bringing new fungal pathogens to humans needs to be taken seriously, says Casadevall — especially if drug-resistant fungi that currently infect species of insects and plants become capable of growing at human body temperature. “Then we find ourselves with organisms that we never knew before, like Candida auris.”

Doctors are already encountering novel fungal infections in people, such as five new-to-medicine species of Emergomyces that have appeared mostly in HIV-infected patients across four continents, and the first record of Chondrostereum purpureum — a fungus that infects some plants of the rose family — infecting a plant mycologist in India. Even though these emerging diseases haven’t been directly linked to climate change, they highlight the threat fungal diseases pose. For Casadevall, the message is clear: It’s time to pay more attention.

Editor’s note: This story was updated on September 27, 2023, to correct a mischaracterization of malaria. It is caused by a parasite, not a virus or a bacterium as was originally stated.

10.1146/knowable-092623-2

Shreya Dasgupta is an independent science journalist based in Bangalore, India.

This article originally appeared in Knowable Magazine, an independent journalistic endeavor from Annual Reviews. Sign up for the newsletter.

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Sam Kreigman and his colleagues made headlines a few years back with their “xenobots”— synthetic robots designed by AI and built from biological tissue samples. While experts continue to debate how to best classify such a creation, Kriegman’s team at Northwestern University has been hard at work on a similarly mind-bending project meshing artificial intelligence, evolutionary design, and robotics.

[Related: Meet xenobots, tiny machines made out of living parts.]

As detailed in a new paper published earlier this month in the Proceedings of the National Journal of Science, researchers recently tasked an AI model with a seemingly straightforward prompt: Design a robot capable of walking across a flat surface. Although the program delivered original, working examples within literal seconds, the new robots “[look] nothing like any animal that has ever walked the earth,” Kriegman said in Northwestern’s October 3 writeup.

And judging from video footage of the purple multi-“legged” blob-bots, it’s hard to disagree:

After offering their prompt to the AI program, the researchers simply watched it analyze and iterate upon a total of nine designs. Within just 26 seconds, the artificial intelligence managed to fast forward past billions of years of natural evolutionary biology to determine legged movement as the most effective method of mobility. From there, Kriegman’s team imported the final schematics into a 3D printer, which then molded a jiggly, soap bar-sized block of silicon imbued with pneumatically actuated musculature and three “legs.” Repeatedly pumping air in and out of the musculature caused the robots’ limbs to expand and contract, causing movement. During testing, the robot could walk half its body length per second—roughly half as fast as the average human stride.

“It’s interesting because we didn’t tell the AI that a robot should have legs,” Kriegman said. “It rediscovered that legs are a good way to move around on land. Legged locomotion is, in fact, the most efficient form of terrestrial movement.”

[Related: Disney’s new bipedal robot could have waddled out of a cartoon.]

If all this weren’t impressive enough, the process—dubbed “instant evolution” by Kriegman and colleagues—all took place on a “lightweight personal computer,” not a massive, energy-intensive supercomputer requiring huge datasets. According to Kreigman, previous AI-generated evolutionary bot designs could take weeks of trial and error using high-powered computing systems. 

“If combined with automated fabrication and scaled up to more challenging tasks, this advance promises near-instantaneous design, manufacture, and deployment of unique and useful machines for medical, environmental, vehicular, and space-based tasks,” Kriegman and co-authors wrote in their abstract.

“When people look at this robot, they might see a useless gadget,” Kriegman said. “I see the birth of a brand-new organism.”

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Neanderthals cooked crab and created art, but they also could have haunted cave lions and used their skins. Some 48,000 year-old puncture wounds on a cave lion’s ribcage suggest that the big cat was killed by a Neanderthal’s wooden spear. The findings are described in a study published October 12 in the journal Scientific Reports and may be the earliest known example of lion hunting and butchering by these extinct humans.

[Related: Sensitive to pain? It could be your Neanderthal gene variants.]

For about 20,000 years, cave lions were the most dangerous animals in Eurasia, with a shoulder height of about 4.2 feet high. They lived in multiple environments and hunted large herbivores including mammoth, bison, hose, and cave bear. They get the name cave lions due to the fact that most of their bones have been found in Ice Age caves. The fearsome creatures went extinct at the end of the last Ice Age, but live on through their bones and the 34,000 rock art panels at Grotte Chauvet in France. 

In 1985, an almost complete cave lion skeleton was uncovered in Siegsdorf, Germany. The bones are believed to be from an old, medium-sized cave lion. There are cut marks across bones including two ribs, some vertebrae, and the left femur, which lead scientists to believe that ancient humans butchered the big cat after it died.  

However, the authors in this new study took another look at the remains. They describe a partial puncture wound located on the inside of the lion’s third rib. The wound appears to match the impact mark left by a wooden-tipped spear. The puncture is angled, which suggests that the spear entered the left of the lion’s abdomen and penetrated its vital organs before impacting the third rib on its right side. 

“The rib lesion clearly differs from bite marks of carnivores and shows the typical breakage pattern of a lesion caused by a hunting weapon,” Gabriele Russo, a study co-author and zooarchaeology PhD student at Universität Tübingen in Germany, said in a statement. 

The characteristics of the puncture wound also resemble the wounds found on deer vertebrae which are known to have been made by Neanderthal spears. The new findings could represent the earliest evidence of Neanderthals purposely hunting cave lions.

“The lion was probably killed by a spear that was thrust into the lion’s abdomen when it was already lying on the ground.” study co-author and University of Reading paleolithic archaeologist Annemieke Milks said in a statement. 

[Related: How many ancient humans does it take to fight off a giant hyena?]

The team also analyzed the findings from a 2019 excavation at the Unicorn Cave–or Einhornhöhle–in the Harz Mountains in Germany. The remains of several animals dating back to the last Ice Age or about 55,000 to 45,000 years ago were found, including some cave lion bones. They looked at bones from the toes and lower limbs of three cave lion specimens. These bones also had cut marks that are consistent with the markings generated when an animal is skinned.

The cut marks suggest that great care was taken while skinning the lion to ensure that the claws remained preserved within the fur. This finding could be the earliest evidence of Neanderthals using a lion pelt, potentially for cultural purposes.

“The interest of humans to gain respect and power from a lion trophy is rooted in Neanderthal behavior and until modern times the lion is a powerful symbol of rulers!” Thomas Terberger, a study co-author and archaeologist at the Universität Göttingen in Germany said in a statement. 

Future studies of cave lion bones could reveal more details of more complex Neanderthal behaviors and how the animal may have laid the basis for cultural development by our own species—Homo sapiens. 

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We’re closer than ever to mapping the entire brain to the microscopic level. Hundreds of neuroscientists across the world recently characterized more than 3,000 human brain cell types as part of the National Institute of Health’s BRAIN Initiative Cell Census Network, publishing almost two dozen papers in four Science journals today. This super-focused attention to detail could unlock many mysteries surrounding that complex organ, such as what happened in our brains to distinguish us from other primates. 

“This is the first large-scale, detailed description of all the different kinds of cells present in the human brain,” says Rebecca Hodge, an assistant investigator at the Allen Institute in Seattle who co-authored multiple studies in the paper package. Her hope is that this brain atlas provides a community resource for scientists to explore how the wide variety of brain cells contribute to health and disease.

Mark Mapstone, a professor of neurology at University of California, Irvine School of Medicine, who wasn’t involved with these studies, likened the new data about the brain to a tourist’s guide. “Imagine navigating an unfamiliar city with a roughly drawn street map containing only the major streets of the downtown compared to navigating the same city with a detailed map extending beyond the downtown to the suburbs and including all highways, two-way and one-way streets, alleyways, sidewalks, location of street signs and traffic signals, speed limits, and location of coffee shops and restaurants,” he says. “Cleary, the latter would make navigation and understanding the city much easier.” This first suite of studies shows three main ways the brain map can be used for biology and medicine.

An evolving brain

A human brain atlas can teach us about our evolutionary history. One study published today in Science used single-nucleus RNA sequencing to measure the gene expression of individual brain cells in humans and five other primate species, including chimpanzees and gorillas. In this method, scientists pull out individual cells from a piece of tissue, break them open to expose the genetic messengers inside, then use tags akin to tiny barcodes to identify that material. “This is the main technology used in some of these papers that are coming out and it’s a technique that’s only been around for the past 10 years,” Hodge says. Getting this genetic profile allows researchers to group clusters of cells into specific types. 

[Related: Psychedelics and anesthetics cause unexpected chemical reactions in the brain]

Our cells’ composition and organization is similar to those of our close relatives. However, the biggest differences seemed to occur in a brain region called the middle temporal gyrus, which is involved in processing semantic memory and language. Humans had higher numbers of projecting neurons in this area compared to other species. What’s more, the researchers highlighted a difference in gene expression that promoted synaptic plasticity, which is the ability of neurons to strengthen brain connections. This feature is an important component for learning and memory, and it might explain how humans developed complex cognitive skills.

There was some variation within humans, too. Another study found the most differences across humans in immune cells called microglia as well as deep-layer excitatory neurons, which are involved in the communication between distant brain regions. Researchers are not quite sure why—one theory is that deep-layer excitatory neurons develop earlier and are more exposed to environmental factors that could diversify their gene patterns. “Everyone’s brain is largely similar. Even though we have the same building blocks, it’s the small number of differences that matter,” says Jeremy Miller, a senior scientist at the Allen Institute, and co-author of the study. “We’re now starting to understand how important these changes are and figuring out what makes us uniquely human.”

Animal models

Because human brains share many features with other mammals, neurologists frequently use the small brains of mice to study diseases. The one problem, Miller says, is that mice don’t naturally develop neurodegenerative diseases common in humans. Scientists who want to study Alzheimer’s disease, for example, would need to manipulate multiple mouse genes to cause the kind of brain pathology seen in older people. This requires a comprehensive understanding of how cell types in the brain work together and how they change in the context of disease. 

[Related: How your brain conjures dreams]

Much brain research in mice focuses on the neocortex, responsible for higher cognitive function. It might seem reasonable to assume that much of the brain’s cellular complexity appears here. But this doesn’t seem to be the case. In one of the first studies to create a cell map of the entire adult brain, neuroscientists have found high levels of diversity in older evolutionary structures such as the midbrain, which is involved in movement, vision, and hearing, and the hindbrain, which governs vital bodily functions such as breathing and heart rate. In subcortical areas, there also appears to be a supercluster of cells called splatter neurons that control innate behaviors and physiological functions. Replicating the complexity of these particular brain regions in animal models could help better identify the cellular origins of human diseases. 

Personalized medicine

Imagine a future where treatments are tailored to someone’s specific needs. To do that, scientists would use a person’s genetic profile, rather than characteristics such as weight or age, to inform any medical decisions. Clinicians could also use this genetic information to identify the risks of potential diseases and provide early preventative measures. 

“A detailed brain atlas can help us understand what successful brain function looks like so we can maximize brain cells and circuits that promote brain heath,” Mapstone says. “Addressing brain disease and promoting brain health can be more easily accomplished if we know how these cells are organized. “

Doctors are already using people’s genetic information to assess whether patients would be good candidates for a particular cancer treatment or to find the proper dose of a drug. This may soon include testing for neurological conditions. One study, which analyzed 1.1 million cells in 42 brain regions of neurotypical adults, identified specific neuronal cell types—mainly in the basal ganglia, a region involved in addictive behaviors—that were linked to 19 neuropsychiatric disorders and traits. Those conditions included schizophrenia and bipolar disorder as well as alcohol and tobacco use disorder.

This project is a step in the right direction for advancing research in personalized medicine, says Miller, though he warns this is only one of many to make this a reality for everyone. 

Miller and Hodge are optimistic there will be other versions of the human brain atlas completed in the next five years, as other groups wrap up similar projects. 

But there’s a possibility that we’ll never get the full picture. While Miller finds a half-decade timeframe reasonable, he says there’s always a chance science develops a new technology that could unearth something unexpected about the brain. “We can always do more,” he says.

This post has been updated.

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To avoid the amphibian pile-up that often comes with mating, some female frogs take drastic measures. According to research published October 11 in the journal Royal Society Open Science, female European common frogs will lay completely still and play dead to fend off potential mates. 

[Related: Check out some of the weirdest warty frogs in North America.]

In the study, a team from the Natural History Museum of Berlin in Germany placed a male frog in a box with one large female and one small female and recorded the mating behavior. They observed 54 instances of female frogs being clutched by the males and 83 percent of females tried rotating their body when gripped. About 48 percent of clasped females emitted “release calls” like squeaks and grunts and all of these vocal frogs rotated their bodies. 

Thirty-three percent of the frogs clasped by male expressed tonic immobility. This is when a frog stiffens its outstretched arms and legs to appear dead. The immobility tended to occur alongside both rotating and calling. Smaller females more frequently used all three tactics together than the bigger frogs. 

Interestingly, this unusual behavior had actually been seen centuries before. “I found a book written in 1758 by Rösel von Rosenhoff describing this behavior, which was never mentioned again,” study co-author Carolin Dittrich told The Guardian. “It was previously thought that females were unable to choose or defend themselves against this male coercion. Females in these dense breeding aggregations are not passive as previously thought.”

The team acknowledges that this behavior could also be a way to test a male’s strength and endurance, as those traits could boost their survival chances. They also point out that a larger sample size is needed to see if smaller females are more successful at escaping. 

This playing tactic is also used by other animals as a way to avoid being eaten.

The phrase “playing possum”  refers to a tactic deployed by the North American opossum found in the United States and Canada. When this marsupial is threatened by a predator, it will throw itself onto its back, bare its teeth, drool, and excrete a very bad smelling liquid out of its anal glands to get out of danger. 

North American wood ducks and colorful mallard ducks can immediately collapse when confronted with predators. In a 1975 experiment, 29 out of 50 different wild ducks played dead when they were exposed to captive red foxes. The ducks would also stay still long enough to be brought back to the fox’s den and wait until later to escape. The veteran foxes quickly learned that they needed to quickly deal a fatal injury to ducks that appeared dead.

[Related: Why some tiny frogs have tarantulas as bodyguards.]

Despite being apex predators, multiple species of sharks and rays also exhibit tonic immobility. Lemon sharks will turn onto their back and exhibit labored breathing and an occasional tremor when facing danger. Zebra sharks will also do this and will even stay immobile when being transported. 

Male nuptial gift-giving spiders will display a different death feigning behavior called thanatosis. It’s part of a courtship ritual that begins before mating with potentially cannibalistic female spiders. In a 2006 experiment, the males would “drop dead” when a female approached with interest. When entering thanatosis, the males would collapse and remain completely still, while retaining a gift of prey the male has already caught and wrapped in silk The male only cautiously begins to move when the female ate the gifts and initiated copulation.

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Adjusting to prosthetic limbs isn’t as simple as merely finding one that fits your particular body type and needs. Physical control and accuracy are major issues despite proper attachment, and sometimes patients’ bodies reject even the most high-end options available. Such was repeatedly the case for a Swedish patient after losing her right arm in a farming accident over two decades ago. For years, the woman suffered from severe pain and stress issues, likening the sensation to “constantly [having] my hand in a meat grinder.”

Phantom pain is an unfortunately common affliction for amputees, and is believed to originate from nervous system signal confusions between the spinal cord and brain. Although a body part is amputated, the peripheral nerve endings remain connected to the brain, and can thus misread that information as pain.

[Related: We’re surprisingly good at surviving amputations.]

With a new, major breakthrough in prosthetics, however, her severe phantom pains are dramatically alleviated thanks to an artificial arm built on titanium-fused bone tissue alongside rearranged nerves and muscles. As detailed in a new study published via Science Robotics, the remarkable advancements could provide a potential blueprint for many other amputees to adopt such technology in the coming years.

The patient’s procedure started in 2018 when she volunteered to test a new kind of bionic arm designed by a multidisciplinary team of engineers and surgeons led by Max Ortiz Catalan, head of neural prosthetics research at Australia’s Bionics Institute and founder of the Center for Bionics and Pain Research. Using osseointegration, a process infusing titanium into bone tissue to provide a strong mechanical connection, the team was able to attach their prototype to the remaining portion of her right limb.

Accomplishing even this step proved especially difficult because of the need to precisely align the volunteer’s radius and ulna. The team also needed to account for the small amount of space available to house the system’s components. Meanwhile, the limb’s nerves and muscles needed rearrangement to better direct the patient’s neurological motor control information into the prosthetic attachment.

“By combining osseointegration with reconstructive surgery, implanted electrodes, and AI, we can restore human function in an unprecedented way,” Rickard Brånemark, an MIT research affiliate and associate professor at Gothenburg University who oversaw the surgery, said via an update from the Bionics Institute. “The below elbow amputation level has particular challenges, and the level of functionality achieved marks an important milestone for the field of advanced extremity reconstructions as a whole.”

The patient said her breakthrough prosthetic can be comfortably worn all day, is highly integrated with her body, and has even relieved her chronic pain. According to Catalan, this reduction can be attributed to the team’s “integrated surgical and engineering approach” that allows [her] to use “somewhat the same neural resources” as she once did for her biological hand.

“I have better control over my prosthesis, but above all, my pain has decreased,” the patient explained. “Today, I need much less medication.” 

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Bear enthusiasts of the world have spoken—128 Grazer was just crowned the winner of Fat Bear Week 2023. This is Grazer’s first time wearing the crown, and she beat out runner up 32 Chunk in the fierce Fat Bear Tuesday final by over 85,000 votes.

[Related: It’s Fat Bear season again! This is the best feed to keep up with these hairy giants.]

According to the National Park Service, Grazer is a large adult female, boasting a long straight muzzle, light brown summer fur, and blond ears. During late summer and fall, she is often one of the fattest bears to feed on the plentiful salmon in the Brooks River in Alaska’s Katmai National Park and Preserve.

She is also a particularly defensive mother bear who has raised two litters of cubs. Grazer is known for preemptively confronting and attacking much larger bears—even the large and dominant adult males—to keep her cubs safe. One of Katmai’s adult males named 151 Walker even avoids her, even though she did not have any cubs to protect this season. 

Grazer is the third female bear, or sow, to win the tournament. In 2019, 435 Holly was dubbed fattest bear and 409 Beadnose wore the prestigious crown in 2018. Beadnose is believed to have died in the five years since. 

“The girls did really well this year,” media ranger at Katmai National Park and Preserve Naomi Boak told The Washington Post. “It was the year of the sow.”

Like any competition, this year’s voting was packed with twists and turns. Four-time Fat Bear Week Champion 480 Otis was ousted on Friday October 6. Otis is the oldest and among the park’s most famous bears. This year, he arrived at Brooks River very skinny, but transformed into a thick bear. Otis was beaten by bear 901, a new mom and the 2022 runner up. 

On Saturday October 7, the 2022 winner bear 747 was defeated by Grazer, who went on to beat 901, Holly, and Chunk in the Final Four. 

[Related: How scientists try to weigh some of the fattest bears on Earth.]

First launched by the National Park Service in 2014 as Fat Bear Tuesday, Fat Bear Week is an annual tournament-style bracket competition where the public votes for their favorite chubby bear. Its goal is to celebrate the Brooks River brown bears at Katmai in southern Alaska and its remarkable ecosystem. It was expanded Fat Bear Week in 2015, following the first year’s success. In 2022, over one million votes were cast all around the world. 

At Katmai, bears are drawn to the large number of salmon readily available from late June through September. Salmon have long since been the lifeblood of the area, supporting Katmai’s people, bears and other animals. Fat bears exemplify the richness of this area, a wild region that is home to more brown bears than people along with the largest, healthiest runs of sockeye salmon left on the planet. The daily lives of the Brooks River bears can be followed via eight live-streaming cameras on explore.org from June through October. 

The winners, and all the bears, now get six months of restful solitude as winter approaches. 

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In the years since the Neanderthal genome was first sequenced, geneticists have been peering into the past to look for traces of this extinct group of humans within our genes. The presence of these ancient genes could make carriers more at risk for severe COVID-19, influence nose shape, and even make some people more sensitive to pain. 

[Related: Neanderthal genomes reveal family bonds from 54,000 years ago.]

A new study published October 10 in the journal Communications Biology found that those carrying three Neanderthal gene variants are actually more sensitive to pain from skin pricking after prior exposure to mustard oil. In this case, mustard oil acts as an agonist, or a substance that initiates a physiological response. Adding it to the skin causes a quick response by neurons called nociceptors that create a sense of pain. 

SCN9A is a key gene in the perception of pain that is located on chromosome 2. It is highly expressed nociceptors that are activated when a sharp point or something hot is applied to the body. The neurons encode proteins within the body’s sodium channel and alert the brain which leads to the perception of pain. Earlier research found three variations in the SCN9A gene–M932L, V991L, and D1908G–in sequenced Neanderthal genomes and reports of greater sensitivity to pain among the living humans who have all three of these variants. 

“It has been shown in previous studies that some rare mutations in this gene that stop the channel from working can cause insensitivity to pain,” study co-author and University of Oxford neuroscientist David Bennett tells PopSci. “We were, however, interested in these other mutations, which were shown to have an opposite effect of enhancing the activity of this channel, thus leading their carriers to be somewhat more sensitive than non-carriers.”

According to Andrés Ruiz-Linares, study co-author and University College London human geneticist, earlier studies show that the mutations are quite rare in the British populations, but they are very frequent in Latin American populations. 

“We thus realized that we had, in our hands, the perfect dataset to not only replicate their study but also go further and identify the pain modality that was at work here,” Ruiz-Linares tells PopSci. 

In the study, the team measured the pain thresholds of 1,963 individuals from Colombia in response to a range of stimuli. The D1908G variant was present in roughly 20 percent of chromosomes within this population. About 30 percent of chromosomes carrying this variant also carried the M932L and V991L variants. All three variants were associated with a lower pain threshold in response to skin pricking after the skin was exposed to mustard oil, but not in response to pressure or heat. Additionally, carrying all three of these variants was associated with greater pain sensitivity than carrying only one of them. 

[Related: Neanderthals were likely creating art 57,000 years ago.]

The team then analyzed the genomic region that houses SCN9A using genetic data from 5,971 individuals from Peru, Chile, Brazil, Colombia, and Mexico. They found that the three Neanderthal variants were more common in regions where the population had a higher proportion of Native American ancestry, such as the Peruvian population.

“They [the mutations] have a rather wide range in these countries, from 2 to 42 percent,” study co-author and University College London statistical geneticist Kaustubh Adhikari tells PopSci. “Up to 18 percent of their populations could carry two copies of the mutation. These are, however, gross estimations. We also know, from the previous study, that these mutations are pretty rare in European populations.”

The team believes that the Neanderthal variants may sensitize the sensory neurons by changing the threshold at which a nerve impulse is generated. The variants could also be more common in populations with higher proportions of Native American ancestry due to random chance as well as population bottlenecks that occurred during when the Americas were first colonized by Europeans. 

“Although Neanderthal intermixing with Europeans is now well-known in popular culture, their genetic contribution to other human groups, such as Native Americans in this case, is less talked about,” study co-author and population geneticist at the National Research Institute for Agriculture, Food and the Environment in France Pierre Faux tells PopSci. “In this study, we saw how important and relevant it is to study genetic backgrounds that are under-represented in medical cohorts.”

Since acute pain can play a role in moderating behavior and preventing further injury, the team is planning additional research to determine if carrying these variants and having greater sensitivity to pain was advantageous during human evolution. Understanding how these variants work could also help physicians understand and treat chronic pain.

“Genes are just one of many factors, including environment, past experience, and psychological factors, which influence pain,” says Bennet. 

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A new marine snail that would make the late great Jimmy Buffet proud has been discovered in the Florida Keys. The lemon-colored snail is named Cayo margarita after the Spanish word for “small, low island” and the tropical drink Buffet sings about in one of his biggest hits. The new and real resident of the fictional Margaritaville is described in a study published October 9 in the journal PeerJ.

[Related: This cone snail’s deadly venom could hold the key to better pain meds.]

Marine smells are distantly related to the land-dwelling gastropods in gardens around the world. The margarita snails come from a group nicknamed worm snails, since they spend many of their lives living in one place. Worm snails also do not have a protective covering found in other snails called an operculum. This body part allows the snails to retreat further inside their shell and keep their bodies moist.

“Worm snails are just so different from pretty much any other regular snail,” study co-author Rüdiger Bieler tells PopSci. “These guys are sitting in the middle of the coral reef where everybody is out trying to eat them. And they’ve given up that protection and just advertise with their bright colors.”

Bieler is a marine biologist and curator of invertebrates at the Field Museum in Chicago who has spent 40 years studying the Western Atlantic’s invertebrates. Even after decades studying the region, these worm snails were hiding in plain sight during dive trips, largely because these snails are kind of the ultimate introverts.

Once juvenile worm snails find a spot to hunker down and they cement their shell to a hard surface never really move again. “Their shell continues to grow as an irregular tube around the snail’s body, and the animal hunts by laying out a mucus web to trap plankton and bits of detritus,” Bieler explains. 

Bieler and the rest of the international team of researchers came across the lemon-yellow snails in the Florida Keys National Marine Sanctuary and a similar lime-colored snail in Belize. Within the same species of snails, it is possible to get many different colors. There can also be color variations in a single population or even cluster of snails. Bieler believes that they may do this to confuse some of the coral reef fish that can see color so that they do not have a clear target. Some may use their hue as a warning color.  

The team initially believed that the lime-green and lemon-yellow snails were different species, but DNA sequencing revealed just how unique they are. This new yellow species belongs to the same family of marine snails as the invasive snail nicknamed the “Spider-Man” snail. This same team found these snails in 2017 on the Vandenberg shipwreck off the Florida Keys.

[Related: Invasive snails are chomping through Florida, and no one can stop them.]

The snails in this new Cayo genus also share a key trait in common with another worm snail genus called Thylacodes. The species Thylacodes bermudensis is found near Bermuda, and while only distantly related to their Floridaian and Belizean cousins, they have small colored heads and mucus that pop out of tubular shells. This might work as a deterrent to keep corals, anemones, and other reef fish from getting too close. The mucus has some nasty metabolites in it which might explain why these snails risk exposing their heads. 

The study and the new snails described in it help illuminate the stunning biodiversity of the world’s coral reefs, which are under serious threat due to climate change and the record warm ocean temperatures this summer. 

“These little snails are kind of beacons for biodiversity that need to be protected because many of them are dying out before we even get a chance to study them,” says Biler. 

It is also an important lesson in always looking right under your nose for discovery.

“I’ve been doing this for decades. We still find new species and previously unknown morphologies right under our feet,” says Biler. “This [discovery] was at snorkeling depth and in one of the most heavily touristed areas in the United States. When you look closely, there are still new things.”

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The internet has recently fallen in love with South America’s charismatic rodents called Capybaras. From catchy songs to memes, it’s hard not to see the chunky charmers in your feed these days. Here are some fun facts about these captivating creatures to inform your scrolling.

[Related: Capybara spent a month on the lam after escape from Toronto Zoo.]

Where can I see a capybara in the wild?

Capybaras are the largest rodent in the world can be found east of the Andes Mountains and the riverbanks in Central and South America from Panama to Argentina. Since they are semi-aquatic like beavers and hippos, capybaras typically live beside ponds, swamps, marshes, or wherever standing water is available. They are also called “water hogs” or “capys” and can even stay under water for more than five minutes to escape from predators like anacondas and jaguars. 

They have been known to encroach further into human territory as their habitat is dwindling. Since 2020, hundreds of capybaras have taken over Nordelta, a private and gated neighborhood outside of Buenos Aires. The rodents had always been around, but remained hidden. The lockdowns triggered by the COVID-19 pandemic enabled the furry capys to spread and flourish in the posh neighborhood’s parks. 

Multiple zoos in the United States, including the Cincinnati Zoo and Botanical Garden (also home to some famous hippos), Southwick’s Zoo in Massachusetts, and the Cape May County Park and Zoo in New Jersey, are home to a handful of adorable specimens as well. 

Do capybaras really eat their own poop?

Yes, among other things. They eat their poop for beneficial bacteria that helps their stomach break down the thick fiber from their other food sources such as reeds and grains, according to the San Diego Zoo. 

Like other rodents, capybaras have ever-growing front teeth. They use their sharp and long chompers to graze on grass and water plants. When fresh grasses and water plants dry up during the dry season, they eat squashes, melons, reeds, and grains. An adult can eat about six to eight pounds of grasses per day. 

How big are capys?

There are two known species of capybara: Hydrochoerus hydrochaeris and Hydrochoerus isthmius.  Of the two, H.hydrochaeris is the largest living rodent in the world. It can grow up to 4.3 feet long and weigh a whopping 174 pounds. H. isthmius is a bit smaller. It can grow to about 3 feet long and weigh closer to 62 pounds.

[Related: These prehistoric rodents were social butterflies.]

Can I own a capybara as a pet in the United States?

It depends what state you call home. They are currently legal with restrictions in some states including Texas, Pennsylvania, Nevada, Arizona, and Georgia. California and New York have more stringent rules, including that the animals can only be obtained by those with an approved scientific or educational reason. While ownership may be legal at the state, it may be illegal at the city level. 

Yahoo Finance estimates that the initial cost to buy a capy on the exotic animal market is about $1,000 per animal, while other estimates place the cost at $8,000. Vet bills can easily stretch between $600 to $1,000 each year?? and owners need to keep in mind the six to eight pounds of food that they can eat per day. Capybaras are also social animals, so owners need to be prepared to take in more than one for their pet to thrive. 

What are capys all over my feed?

Basically, capybaras are kind of the new Baby Shark. The song Capybara from Russian artist Сто-Личный Она-Нас went viral on TikTok earlier this year. Listen at your own risk, as it is a textbook earworm that will be stuck in your head for days.

Popular videos include a capybara sparring with a platypus and jumping into above ground pools. They are also the stars of pop culture memes, including one celebrating the billion dollar hit movie Barbie. 

They are also known for being some of the friendliest critters in the animal kingdom. They are very social and live together in herds of 10 to 20 animals. They spend time together cuddling, playing, socializing, and grooming one another. They have even been known to try to use alligators to hitch a ride. 

It also doesn’t hurt that they are really cute. In an era of doom scrolling, sometimes it’s just nice to look at their hippo-like eyes and ears as they look above the water. 

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Meet Garumbatitan morellensis, a new species of large sauropod dinosaur. The Giganotosaurus relative called the present-day Iberian Peninsula home about 122 million years ago. The remains of this titan were discovered in Morella, Spain, and this discovery could help fill in some major evolutionary gaps. The findings were described in a study published September 28 in the journal Zoological Journal of the Linnean Society.

[Related: Cushy feet supported sauropods’ gigantic bodies.]

G. morellensis belongs to the sauropod group of dinosaurs, which includes some well-known favorites like Diplodocus and Brachiosaurus. Sauropods were four-legged Early Jurassic and Cretaceous Era dinos known for their long necks that could reach up to 49 feet long in some species and lengthy tails. G. morellensis is also a member of a subgroup of sauropods known as titanosaurs. These giants were the largest of an already big group and titanosaurs survived right up until the asteroid that wiped out the dinosaurs struck about 66 million years ago.

This new dinosaur’s remains were found and excavated in the Sant Antoni de la Vespa fossil-site in 2005 and 2008. This fossil deposit is home to one of the largest concentrations of sauropod dinosaur remains that date back to the Lower Cretaceous period in Europe (about 145 million to 66 million years ago). Scientists found the remains of a giant unidentified sauropod in Portugal in 2022 that could be Europe’s oldest known dinosaur fossil at 150 million-years-old. 

The team of paleontologists from Portugal and Spain found the remains of three G. morellensis individuals and one other sauropod. Their lucky find included a rare set of footprints. They also uncovered giant vertebrae, leg bones, and two near-complete sets of foot bones. 

“One of the individuals we found stands out for its large size, with vertebrae more than one meter wide [3.2 feet], and a femur that could reach two meters [6.5 feet] in length. We found two almost complete and articulated feet in this deposit, which is particularly rare in the geological record,” study co-author and University of Lisbon paleontologist Pedro Mocho said in a statement. 

G. morellensis was probably close to an average-size titanosaur and could have been near 94 feet long. Its leg shape and foot bones suggest that it was one of the more primitive sauropods from a subgroup called Somphospondyli, according to the authors. Somphospondylan fossils have been found on every present-day continent, but paleontologists are not sure where they originated. This discovery of such an early specimen in Spain points to Europe as a possible origin point for this subgroup, but more evidence is needed.  

[Related: Europe’s largest dinosaur skeleton may have been hiding in a Portuguese backyard.]

This discovery also highlights how complex the evolutionary history of sauropods in the Iberian Peninsula and the rest of Europe is. Species related to these lineages have been found in Asia, North America, and possibly Africa. This points to a potentially long period of dinosaur dispersal within continents and this fossil deposit might fill in some major gaps of evolutionary history. 

“The future restoration of all fossil materials found in this deposit will add important information to understand the initial evolution of this group of sauropods that dominated dinosaur faunas during the last million years of the Mesozoic era,” study co-author and Universidad Nacional de Educación a Distancia in Madrid paleontologist Francisco Ortega said in a statement.

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In 2006, a cluster of mysterious dark spots on a lakebed of White Sands National Park in New Mexico caught the attention of archaeologists. The shapes stroked their curiosity until they eventually excavated the site three years later. Waiting for them was one of the rarest and soon-to-be controversial discoveries in history—a set of fossilized human footprints. 

The preserved markings were found on the shore of a lake that existed during the most recent ice age, and could be one of the earliest signs of biped migration to North America. Some experts claim they are the steps of the Clovis people, the continent’s first human inhabitants and the ancestors for most Native Americans. The Clovis are thought to have made the journey to North America 13,000 to 13,500 years ago using a land bridge that connected Asia to Alaska. From there, they continued to move as far down south as Central and South America. 

“This was groundbreaking to the archaeologic community, and it was also a tough pill to swallow,” says Kathleen Springer, a research geologist for the United States Geological Survey (USGS) who helped analyze the fossilized steps. “Having 23- to 21,000-year-old footprints is much earlier than the prevailing paradigm of Clovis or pre-Clovis that are known in this part of North America.”

The finding initially received some pushback. When the results were first revealed in 2021, concerned archaeologists wrote comments and papers challenging the results, citing the need for better evidence. More specifically, they criticized the study method and the decision to use radiocarbon dating on the seeds of an aquatic plant that was excavated from the same site. 

Part of the debate came down to an isotope that’s often used in archaeological work. Carbon-14 forms in the air and is introduced to photosynthetic plants and the animals that eat them. When flora and fauna are alive, they have the same amount of carbon-14 as the Earth’s atmosphere; when they die, it decays in their remains. Scientists can then measure how much of the isotope is left and use that metric to calculate an organism’s approximate age. But as some experts have pointed out, aquatic plants like the ones sampled at White Sands can get carbon from the water they live in, which can skew the measurements and make a specimen seem older than it really is.

“It’s called the hard water effect, and it’s a really well-known problem with radiocarbon dating,” explains Jeffrey Pigati, a USGS research geologist who co-authored both studies with Springer. He says the general argument with the first paper is that there were large hard-water effects that made them overestimate the age of the footsteps when they should have been around 15,000 or 17,000 years old.

The COVID pandemic delayed many of the follow-up experiments Pigati and Springer wanted to complete when investigating the site in 2020. Three years later, they finally did with two new methods that corroborate their original estimate of the footprints’ age: radiocarbon dating of pollen and luminescence dating.

To avoid heavy-water effects, the team extracted pollen grains from the same sediment as the White Sands footprints. According to Pigati, this is a time-consuming and laborious process because it involves breaking down rock into one cubic centimeter of material and separating pollen from other organic material before measuring carbon-14 levels. Additionally, pollen is extremely light—experts need to sample thousands of grains to meet the minimum mass requirement for a single radiocarbon measurement. In total, they successfully isolated 75,000 pollen grains. When the they compared the measurements to ones from the seeds of the aquatic plant, the ages matched.

The second technique was optically stimulated luminescence (OSL) dating. Unlike radiocarbon dating, OSL dating is based on the buildup of luminescence properties in quartz crystals over time; in some rare cases, it can date sediments as far back as 400,000 years ago. The USGS team dated three different mineral samples from the same area where the footprint was discovered and calculated ages that were similar to the ones measured in the seeds.

Still, this does not mean we have a complete picture of our species’ migration to North America. Paulette Steeves, an archaeologist and author of The Indigenous Paleolithic of the Western Hemisphere, who was not involved in the White Sands research, says there are archaeological sites in both North and South America that date to as early as 11,000 to 200,000 years ago. While she argues it’s not the oldest sign of human habitation in the Americas and may not be proof of the first Indigenous group, “the White Sands footprints site is a great addition to the record of early people in the Western Hemisphere.”

The footprints are just one piece of the puzzle. Archaeologists still don’t know exactly how people lived in the middle of an ice age and weathered harsh climate. Future projects at White Sands could include tracking the footprints to a campsite or further scouring the area for stone tools that could give some insight into their survival. “Every day we’re working out there is amazing because you never know what is going to be discovered,” Pigati says. “This is all a part of science in action.”

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Wearable sensors can already monitor a variety of important health characteristics. But they are still far short when it comes to detecting hormonal levels, particularly for women. A new device designed by researchers at Caltech, however, is specifically tailored to measure one of women’s most vital and influential hormones. According to the team’s study, recently published in Nature Nanotechnology, their new wearable sensor can detect and assess users’ estradiol levels by just analyzing sweat droplets.

Estradiol, the most potent form of estrogen, is a crucial component in women’s health. Not only is it necessary in regulating reproductive cycles and ovulation, but this hormone’s levels are directly correlated to issues ranging from depression, to osteoporosis, to even heart disease. Currently, estradiol monitoring requires blood or urine samples collected either in-clinic or at-home. In contrast, Caltech’s new sensor, created by assistant professor of medical engineering Wei Gao, only needs miniscule amounts of sweat collected via extremely small automatic valves within its microfluidic system.

[Related: This organ-failure detector is thinner than a human hair.]

The sensor’s reliance on sweat to measure estradiol isn’t only impressive due to its non-invasive nature; according to Caltech’s announcement, the hormone is about 50 times less concentrated in sweat than in blood.

The wearable’s monitoring system utilizes aptamers—short, single-strand DNA capable of binding to target molecules like artificial antibodies. Gao’s team first attached aptamers to a surface imbued with inkjet-printed gold nanoparticles. The aptamers then could bind with targeted molecules—in this case, estradiol. Once connected, the molecule gets recaptured by other titanium carbide-coated gold nanoparticles known as “MXenes.” The resultant electrical signal can be wirelessly measured and correlated to estradiol levels via a simple-to-use smartphone app.

To actually collect the sweat samples, the sensor uses tiny channels controlled by automatic valves to allow only fixed amounts of fluid into the sensor. To take patients’ sweat composition differences into consideration, the device also consistently calibrates via information collected on salt levels, skin temperature, and sweat pH.

This isn’t Gao’s first sweat sensor, either—previous variants also could detect the stress hormone cortisol, COVID-19, as well as a biomarker that indicates inflammation.

“People often ask[ed] me if I could make the same kind of sweat sensor for female hormones, because we know how much those hormones impact women’s health,” Gao said via Caltech’s announcement. With further optimization, the new estradiol sensor could help users attempting to naturally or in vitro conceive children, as well as aid those necessitating hormone replacement therapies. According to Gao, the team also intends to expand the range of female hormones they can detect, including another ovulation-related variant, progesterone.

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AI programs can already respond to sensory stimulations like touch, sight, smell, and sound—so why not taste? Engineering researchers at Penn State hope to one day accomplish just that, in the process designing an “electronic tongue” capable of detecting gas and chemical molecules with components that are only a few atoms thick. Although not capable of “craving” a late-night snack just yet, the team is hopeful their new design could one day pair with robots to help create AI-influenced diets, curate restaurant menus, and even train people to broaden their own palates.

Unfortunately, human eating habits aren’t based solely on what we nutritionally require; they are also determined by flavor preferences. This comes in handy when our taste buds tell our brains to avoid foul-tasting, potentially poisonous foods, but it also is the reason you sometimes can’t stop yourself from grabbing that extra donut or slice of cake. This push-and-pull requires a certain amount of psychological cognition and development—something robots currently lack.

[Related: A new artificial skin could be more sensitive than the real thing]

“Human behavior is easy to observe but difficult to measure. and that makes it difficult to replicate in a robot and make it emotionally intelligent. There is no real way right now to do that,” 

Saptarshi Das, an associate professor of engineering science and mechanics, said in an October 4 statement. Das is a corresponding author of the team’s findings, which were published last month in the journal Nature Communications, and helped design the robotic system capable of “tasting” molecules.

To create their flat, square “electronic gustatory complex,” the team combined chemitransistors—graphene-based sensors that detect gas and chemical molecules—with molybdenum disulfide memtransistors capable of simulating neurons. The two components worked in tandem, capitalizing on their respective strengths to simulate the ability to “taste” molecular inputs.

“Graphene is an excellent chemical sensor, [but] it is not great for circuitry and logic, which is needed to mimic the brain circuit,” said Andrew Pannone, an engineering science and mechanics grad student and study co-author, in a press release this week. “For that reason, we used molybdenum disulfide… By combining these nanomaterials, we have taken the strengths from each of them to create the circuit that mimics the gustatory system.”

When analyzing salt, for example, the electronic tongue detected the presence of sodium ions, thereby “tasting” the sodium chloride input. The design is reportedly flexible enough to apply to all five major taste profiles: salty, sour, bitter, sweet, and umami. Hypothetically, researchers could arrange similar graphene device arrays that mirror the approximately 10,000 different taste receptors located on a human tongue.

[Related: How to enhance your senses of smell and taste]

“The example I think of is people who train their tongue and become a wine taster. Perhaps in the future we can have an AI system that you can train to be an even better wine taster,” Das said in the statement.

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Over 1,500 animal species, from bonobos to sea urchins to penguins are known to engage same-sex sexual behavior. Still, scientists don’t understand exactly how it came to be or why it happens. While some say the behavior might have existed since the animal kingdom first arose more than half a billion years ago, it may have actually evolved repeatedly in mammals. A study published October 3 in the journal Nature Communications suggests that the behavior possibly plays an adaptive role in social bonding and reducing conflict, and evolved multiple times.

[Related: A massive study confirms no one ‘gay gene’ controls sexual preference.]

The behavior is particularly prevalent in nonhuman primates. It has been observed in at least 51 species from small lemurs up to bigger apes. For one population of male macaques, same-sex sexual behavior may even be a common feature of reproduction and is related to establishing dominance within groups, handling a shortage of different-sex partners, or even reducing tension following aggressive behavior. 

In this new study, the team from institutions in Spain surveyed the available scientific literature to create a database of records of same-sex sexual behavior in mammals. They traced the behavior’s evolution across mammals and tested for any evolutionary relationships with other behaviors. 

The team found that same-sex sexual behavior is widespread across mammal species, occurs in similar frequency in both males and females, and likely has multiple independent origin points. This analysis found that the behavior helps establish and maintain positive social relationships in animals including chimpanzees, bighorn sheep, lions, and wolves.

“It may contribute to establishing and maintaining positive social relationships,” study co-author José Gómez told The New York Times. “With the current data available, it seems that it has evolved multiple times.” Gómez is an evolutionary biologist at the Experimental Station of Arid Zones in Almería, Spain. 

Importantly, they caution that the study should not be used to explain the evolution of sexual orientation in humans. This research focused on same-sex sexual behavior defined as short-term courtship or mating interactions, instead of a more permanent sexual preference. 

Additionally, male same-sex sexual behavior was likely evolved in species with high rates of male adulticide–-when adult animals kill other adults. The team believes that this suggests the behavior may be an adaptation meant to mitigate the risks of violent conflict between males.

Harvard University primatologist Christine Webb, who did not participate in the study, told The Washington Post that the findings add to other research and widen the scope of what it means for a behavior to be considered adaptive.

[Related: Same-sex mounting in male macaques can help them reproduce more successfully.]

“This general question of evolutionary function—that behavior must aid in survival and reproduction—what this paper is arguing is that reaffirming social bonds, resolving conflicts, managing social tensions, to the extent that same-sex sexual behavior preserves those functions—it’s also adaptive,” Webb said. 

Webb also added that it makes sense that other animals would have sex for a variety of reasons the way that humans do.

The authors caution that these associations could also be driven by other evolutionary factors. Same-sex sexual behavior has also only been carefully studied in a minority of mammal species, so our understanding of the evolution of same-sex sexual behavior may continue to change as more mammalian species are studied.

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Earth’s amphibians are in serious trouble, but there is still time to save this unique class of animals. A study published October 4 in the journal Nature finds that two out of five amphibians are threatened with extinction and they continue to be the most threatened class of vertebrates. However, the new research also found that since 1980, the extinction risk of 63 species has been reduced due to conservation interventions.

[Related: Why you can’t put a price on biodiversity.]

“This proves that conservation works and it’s not all bad news,” Jennifer Luedtke, a study co-author and the manager of IUCN Red List Assessments at conservation organization Re:wild, said during a press conference. “We found that habitat protection alone is not sufficient. We need to mitigate the threats of disease and climate change.”

A check-up for amphibians

The findings are part of Global Amphibian Assessment II, an international series of conservation analyses based on evaluations of the 8,011 amphibian species listed on the IUCN Red List. The first Global Amphibian Assessment was published in 2004 and found that amphibians are Earth’s most threatened class of vertebrates. This second report confirms that the smooth-skinned animals are still more threatened than birds or mammals.

In the study, the team found that 118 species have been driven to extinction between 2004 and 2022. About 40 percent of the species studied are still categorized as threatened. This study also covers about 94 percent of the known amphibian species in 2022. According to Luedtke, about 155 new amphibian species are discovered every year, so there will likely be more species to add to the next Global Amphibian Assessment. 

Climate change and associated habitat loss are the primary driver of these declines. The team estimates that current and projected climate change effects are responsible for 39 percent of status deteriorations since 2004. Habitat loss has affected roughly 37 percent of species in the same period. 

Why amphibians are so vulnerable to climate change

Amphibians’ unique skin puts them in more danger in the face of a changing planet, since they use their skin to breathe. Increased frequency and intensity of storms, floods, droughts, changes in moisture levels and temperature, and sea level rise can all affect their very important breathing sites.

“They don’t have any protection in their skin like feathers, hair, or scales. They have a high tendency to lose water and heat through their skin,” Patricia Burrowes, a study co-author and herpetologist formerly with the University of Puerto Rico, said during a press conference. “The majority of frogs are nocturnal, and if it’s very hot, they will not come out because they will have lost so much water even in their retreat sites that they don’t have the energy to go out to feed. They won’t grow and won’t have energy to reproduce. And that can have demographic impacts.”

[Related: Hellbender salamanders may look scary, but the real fright is extinction.]

Extinctions have continued to increase with 37 documented in 2022. By comparison 23 species were reported extinct by 1980 and 33 in 2004. According to the report, the most recent species to go extinct were the frogs Atelopus chiriquiensis from Costa Rica and western Panama and Taudactylus acutirostris from Australia.

“Amphibians are essential parts of the ecosystem in a variety of ways, one of them being their role in the food web,” Kelsey Neam, study co-author and Re:wild’s Species Priorities and Metrics Coordinator, said during a press conference. “Amphibians are prey for many species and without amphibians, those animals lose a major source of their food and they are preying upon other animals like insects and other invertebrates. Without them to fulfill that niche, we will see a collapse of the food web.”

Amphibian pandemics

The most heavily affected amphibians were salamanders and newts, with three out of five salamander species at risk for extinction. While habitat loss is also the primary threat to salamanders, they are also particularly vulnerable to a disease called chytridiomycosis. It is caused by a fungal pathogen caused by the chytrid fungus that disrupts amphibian’s skin and physiological functions. When infected, amphibians can’t rehydrate properly, which creates an electrolyte imbalance that causes fatal heart attacks.

“Droughts exacerbate the infection intensity,” said Burrowes. “When the frogs have the potential to present some kind of defense mechanism, that defense mechanism is monitored by changes in precipitation and temperature.”

North America is home to the world’s most biodiverse community of salamanders, including a group of lungless salamanders in the Appalachian Mountains. This has conservationists concerned about what would happen if another deadly fungal disease called Batrachochytrium salamandrivorans, or B.sal, arrives in the Americas from Asia or Europe.

‘We know what to do’

The report highlights that the time to help these critical animals is now. The authors point to the Kunming-Montreal Global Biodiversity Framework adopted by 190+ signatory countries at the United Nations Biodiversity Conference in December 2022. The signing nations committed to halting all human induced extinctions, reversing and reducing the extinction risk of species tenfold, and to recovering populations to a healthy level.

“We know what to do. It’s time to really commit the resources to actually achieving the change that we say we want,” said Luedtke. “Amphibians will be the better for it and so will we.”

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Parrots are the chatterboxes of the animal kingdom. These famously social birds can learn new sounds throughout their lives and even produce calls that can be individually recognized by other members of their flock. A new study of monk parakeets found that individual birds have a unique tone of voice similar to humans called a “voice print.” The findings are described in a study published October 3 in the journal Royal Society Open Science.

[Related: The next frontier in saving the world’s heaviest parrots: genome sequencing.]

“It makes sense for monk parakeets to have an underlying voice print,” Simeon Smeele, a co-author of the study and biologist studying parrot social and vocal complexity at the Max Planck Institute of Animal Behavior, said in a statement. “It’s an elegant solution for a bird that dynamically changes its calls but still needs to be known in a very noisy flock.”

In humans, our voice print leaves a unique signature in the tone of our voice across every word we say. These voice prints remain even though humans have a very complex and flexible vocal repertoire. Other social animals also use similar cues to recognize one another. Individual dolphins, bats, and birds have a “signature call” that makes them identifiable to other members of their groups. However, signature calls encode identity in only one call type, and there hasn’t been much evidence that suggests animals have unique signatures that last throughout their entire repertoire of calls. 

Parrots use their tongue and mouth to modulate calls similar to the way humans speak. According to Smeele, “their grunts and shrieks sound much more human than a songbird’s clean whistle.” 

Parrots also live in large groups with fluid membership where multiple birds vocalize at the same time. Members need a way to keep track of which individual is making what sound. The question became if the right physical anatomy coupled with the need to navigate complex social lives, helped parrots evolve a voice print. 

In the study, Smeele and his team traveled to Barcelona, Spain—home to the largest population of individually marked parrots in the wild. The parakeets are considered an invasive species and they swarm Barcelona’s parks in flocks with hundreds of members. The Museu de Ciències Naturals de Barcelona has been marking the parakeets for 20 years and have individually identified 3,000 birds.

The team used microphones to record the calls of hundreds of individuals and collected over 5,000 vocalizations in total. They also re-recorded the same individuals over a period of two years, which revealed the stability of the calls over time.

Using a set of computer models, they detected how recognizable individual birds were within each of the five main call types given by this species (contact, tja, trrup, alarm, and growl). They found high variability in the “contact call” that birds use to broadcast their identity. According to the team, this overturned a long-held assumption that contact calls contain a stable individual signal. The new findings suggested that the parakeets are actually using something else for individual recognition.

[Related: These clever cockatoos carry around toolkits to get to food faster.]

To investigate if voice prints were at play, the team used a machine learning model widely used in human voice recognition. The model detects the identity of the speaker using the quality, or timbre, of their voice. The team trained the model to recognize calls of individual birds that were categorized as “tonal” in sound. They then tested to see if the model could detect the same individual from a separate set of calls that were classified as “growling” in sound. The model was able to identify the individual parrots three times better than expected, providing evidence that monk parakeets do actually have a recognizable, individual voice print. 

While exciting, the authors caution that this evidence is still preliminary. Future experiments and analyses could use the parrot tagging work from the team in Barcelona. The GPS devices could help determine how much individuals overlap in their roaming areas.

“This can provide insight into the species’ remarkable ability to discriminate between calls from different individuals,” study co-author and ecologist from Museu de Ciències Naturals de Barcelona Juan Carlos Senar said in a statement.

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We all know the line: For more than 150 million years, dinosaurs ruled the Earth. We imagine bloodthirsty tyrannosaurs ripping into screaming duckbills, gigantic sauropods shaking the ground with their thunderous footfalls, and spiky stegosaurs swinging their tails in a reign of reptiles so magnificent, it took the unexpected strike of a six-mile-wide asteroid to end it. The ensuing catastrophe handed the world to the mammals, our ancestors and relatives, so that 66 million years later we can claim to have taken over what the terrible lizards left behind. It’s a dramatic retelling of history that is fundamentally wrong on several counts. Let’s talk about some of the worst rumors and what really happened in the so-called “Age of Dinosaurs.”

Myth: Dinosaurs dominated the planet from their origin.

Fact: Dinosaurs started as cute pipsqueaks.

The oldest dinosaurs we know about are around 235 million years old, from the middle part of the Triassic Period. Those reptiles didn’t rule anything. From recent finds in Africa, South America, and Europe, we know that they were no bigger than a medium-sized dog and were lanky, omnivorous creatures that munched on leaves and beetles. Ancient relatives of crocodiles, by contrast, were much more abundant and diverse. Among the Triassic crocodile cousins were sharp-toothed carnivores that chased after large prey on two legs, “armadillodiles” covered in bony scutes and spikes, and beaked, almost ostrich-like creatures that gobbled up ferns.

Even as early dinosaurs began to evolve into the main lineages that would thrive during the rest of the Mesozoic, most were small and rare compared to the crocodile cousins. The first big herbivorous dinosaurs, which reached about 27 feet in length, didn’t evolve until near the end of the Triassic, around 214 million years ago. But everything changed at the end of the Triassic. Intense volcanic eruptions in the middle of Pangaea altered the global climate; the gases released into the air caused the world to swing between hot and cold phases. By then, dinosaurs had evolved warm-blooded metabolisms and insulating coats of feathers, leaving them relatively unfazed through the crisis, while many other forms of reptiles perished. Had this mass extinction not transpired, we might have had more of an “Age of Crocodiles”—or at least a very different history with a much broader cast of reptilian characters. The only reason the so-called Age of Dinosaurs came to be is because they got lucky in the face of global extinction.

Myth: Dinosaurs spanned the entire planet.

Fact: Dinosaurs never evolved to live at sea.

Of course, these ecosystems were built on a foundation of plankton. Without disc-shaped algae called coccoliths, the rest of the charismatic swimmers of the Triassic, Jurassic, and Cretaceous wouldn’t have thrived. It’s the abundant, small forms of life that let charismatic creatures like marine reptiles prosper—a further reminder that the animals that impress us on land or sea wouldn’t exist without various tiny organisms that set the foundations of food webs. What we might see as dominance, in any ecosystem, is really a consequence of many relationships and interactions that often go unnoticed.

Myth: Dinosaurs suppressed the evolution of mammals.

Fact: Mammals thrived throughout the Age of Dinosaurs.

The classic example of dinosaur dominance is a twitchy little mammal chasing an insect through the Cretaceous night. Dinosaurs would gobble up any beast that got too big or was foolish enough to wander out in the daylight, the argument went, so mammals evolved to be small and nocturnal until the asteroid allowed our ancestors and relatives to emerge from the shadows. The small size and insect-hunting adaptations of some Mesozoic mammals were taken as indicators that mammals were constrained by the success of the dinosaurs, preventing them from becoming larger or opening new niches.

In the past 20 years, however, paleontologists have rewritten the classic story to show that mammals and their relatives thrived alongside the dinosaurs. Throughout the Mesozoic there were furry beasts that swam, dug, glided between the trees, and even ate little dinosaurs. Ancient equivalents of squirrels, raccoons, otters, beavers, sugar gliders, aardvarks, and more evolved through the Jurassic and Cretaceous, including early primates that scampered through the trees over the heads of T. rexes. While it’s true that all the Mesozoic mammals we presently know of were small—the largest was about the size of an American badger— researchers have realized that the way our ancient ancestors interacted with each other was much more important to shaping their evolution than the dinosaurs were. In fact, even with the dinosaurs gone, most new mammal species stuck to being small. We get so hung up on size that we’ve missed the real story, closer to the ground.

Myth: Dinosaurs dominated the planet for millions of years.

Fact: No single species can dominate a planet.

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Despite only eating fish, the Southern Resident orcas of the Pacific Northwest’s Salish Sea are known for a perplexing behavior. They harass and even kill porpoises without eating them and scientists are not really sure why. A study published September 28 in the journal Marine Mammal Science looked at over 60 years of data to try and solve this ongoing mystery.

[Related: Raising male offspring comes at a high price for orca mothers.]

While their relatives called transient killer whales eat other organisms including squid, shark, and porpoises, the Southern Resident orcas exclusively eat fish, particularly Chinook salmon. The strange porpoise-harassing behavior was first scientifically documented in 1962. The new study analyzed 78 documented incidents and found three plausible explanations.

Orcas at play

The behavior may be a form of social play for orcas. Like many intelligent species including dogs, elephants, and kangaroos, these whales sometimes engage in playful activities as a way to bond, communicate, or just simply enjoy themselves. Going after porpoises might benefit their group coordination and teamwork.

This theory may be reminiscent of the orcas who became famous for sinking boats in Spain and Portugal. While the Southern Resident killer whales and the whales from the Iberian Peninsula are two different populations with distinct cultures, their affinity for play could be something both populations share, according to the authors of the study. 

Hunting practice

Going after a larger animal like porpoises might help these whales hone their critical salmon-hunting skills. They may view porpoises as moving targets to practice their hunting techniques, even if a meal is not the end result.

Mismothering behavior

The orcas may be attempting to provide care for porpoises that they perceive as either sick or weak. This could be a behavioral manifestation of their natural inclination to help others within their pod. Female orcas have been observed carrying their deceased calves and have been observed carrying porpoises in a similar manner.  

Scientists also call mismothering behavior displaced epimeletic behavior. It could be due to their limited opportunities to care for their young, according to study co-author and science and research director at Wild Orca Deborah Giles. 

“Our research has shown that due to malnutrition, nearly 70 percent of Southern Resident killer whale pregnancies have resulted in miscarriages or calves that died right away after birth,” Giles said in a statement.

An endangered group

Southern Resident killer whales are considered an endangered population. Currently, only 75 individuals exist and their survival is essentially tied to Chinook salmon. A 2022 study found that these orcas have been in a food deficit for over 40 years and another study found that the older and fatter fish are also becoming more scarce in several populations.

“I am frequently asked, why don’t the Southern Residents just eat seals or porpoises instead?” said Giles. “It’s because fish-eating killer whales have a completely different ecology and culture from orcas that eat marine mammals—even though the two populations live in the same waters. So we must conclude that their interactions with porpoises serve a different purpose, but this purpose has only been speculation until now.”

Even with these three theories for the behavior, the team acknowledges that the exact reason behind porpoise harassment may always remain a mystery. What is clear is that porpoises are not a part of the Southern Resident killer whale diet, so eating them is highly unlikely. 

“Killer whales are incredibly complex and intelligent animals. We found that porpoise-harassing behavior has been passed on through generations and across social groupings. It’s an amazing example of killer whale culture,” Sarah Teman, a study co-author and marine mammal biologist with the University of California, Davis School of Veterinary Medicine’s SeaDoc Society, said in a statement. “Still, we don’t expect the Southern Resident killer whales to start eating porpoises. The culture of eating salmon is deeply ingrained in Southern Resident society. These whales need healthy salmon populations to survive.”

However, this research does underscore the importance of salmon conservation in the Salish Sea and the Southern Resident’s entire range. They generally stay near southern Vancouver Island and Washington State, but their range can extend as far as the central California coast and southeastern Alaska.  Maintaining an adequate salmon supply will be vital to their survival and well-being of the Salish Sea ecosystem as a whole.

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Sea turtles have been around for at least 110 million years, yet relatively little is known about their evolution. Two of the most common sea turtles on Earth are olive ridley and Kemp’s ridley turtles that belong to a genus called Lepidochelys that could help fill in some of the gaps of sea turtle biology and evolution. A team of paleontologists not only discovered the oldest known fossil of turtle from the Lepidochelys genus, but also found some traces of ancient turtle DNA. The findings are detailed in a study published September 28 in the Journal of Vertebrate Paleontology.

[Related: 150 million-year-old turtle ‘pancake’ found in Germany.]

The DNA comes from the remains of a turtle shell first uncovered in 2015 in the Chagres Formation on Panama’s Caribbean coast. It represents the oldest known fossil evidence of Lepidochelys turtles. The turtle lived approximately 6 million years ago, curing the upper Miocene Epoch. At this time, present day Panama’s climate was getting cooler and drier, sea ice was accumulating at Earth’s poles, rainfall was decreasing, sea levels were falling.

“The fossil was not complete, but it had enough features to identify it as a member of the Lepidochelys genus,” study co-author and Universidad del Rosario in Bogotá, Colombia paleontologist Edwin Cadena tells PopSci. Cadena is also a research associate at the Smithsonian Tropical Research Institute in Panama.

The team detected preserved bone cells called osteocytes. These bone cells are the most abundant cells in vertebrates and they have nucleus-like structures. The team used a solution called DAPI to test the osteocytes for genetic material.

“In some of them [the osteocytes], the nuclei were preserved and reacted to DAPI, a solution that allowed us to recognize remains of DNA. This is the first time we have documented DNA remains in a fossilized turtle millions of years old,” says Cadena.

According to the study, fossils like this one from vertebrates preserved in this part of Panama are important for our understanding of the biodiversity that was present when the Isthmus of Panama first emerged roughly 3 million years ago. This narrow strip of land divided the Caribbean Sea and the Pacific Ocean and joined North and South America. It created a land bridge that made it easier for some animals and plants to migrate between the two continents.

[Related: Hungry green sea turtles have eaten in the same seagrass meadows for about 3,000 years.]

This specimen could also have important implications for the emerging field of molecular paleontology. Scientists in this field study ancient and prehistoric biomatter including proteins, carbohydrates, lipids, and DNA that can sometimes be extracted from fossils. 

Molecular paleontology aims to determine if scientists can use this type of evidence to determine more about the organisms than their physical shape, which is typically what is preserved in most fossils. Extracting this tiny material from bones was critical in sequencing the Neanderthal genome, which earned Swedish scientist Svante Pääbo the 2022 Nobel prize in physiology or medicine.

“Many generations have grown up with the idea of extracting and bringing back to life extinct organisms,” says Cadena. “However, that is not the real purpose of molecular paleontology. Instead, its goal is to trace, document, and understand how complex biomolecules such as DNA and proteins can be preserved in fossils.”

This new turtle specimen could help other molecular paleontologists better understand how soft tissues can be preserved over time. It could also shift the idea that original biomolecules like proteins or DNA have a specific timeline for preservation in fossils and encourage re-examining older specimens for traces of biomolecules. 

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Sci-fi author Brian Herbert once wrote, “The only guarantee in life is death, and the only guarantee in death is its shocking unpredictability.” These words ring true to researchers who investigate what happens in a person’s final moments—and the frustration that comes with these studies. One big problem almost always gets in the way: How do you ask people what dying feels like when they’re no longer here? 

Because we haven’t yet figured out how to communicate with the dead, the best-case scenario is talking to people who have had a close brush with death. They often mention seeing bright lights, their life flashing before their eyes, or visions of deceased loved ones. Some have even reported spotting the Grim Reaper by their bedside. It’s a paradoxical situation, says Kevin Nelson, a professor of neurology at the University of Kentucky: A few perceptions are common—a shining light, for instance—but the near-death experience is unique to each individual.

There’s still a lot of mystery when it comes to the cause, but the field is progressing thanks to people who have allowed scientists to study their brains in these situations. People who have survived these close calls say the encounter can be life-changing. One thing is certain: medical experts say near-death experiences are not a figment of the imagination. 

And figuring out the mechanisms behind this phenomenon goes beyond general curiosity. One goal is to better understand how cardiac arrests happen. It could also potentially save lives, because doctors would have more knowledge for when to continue resuscitations after a patient’s heart stops.

“The research not only benefits our understanding of consciousness, but also in understanding the importance of the heart, lung, and brain in our everyday physiology,” says Jimo Borjigin, an associate professor of neurology at the University of Michigan Medical School.

Unreal recall

A near-death experience can happen to anyone. In fact, 1 in 10 people have reported sharper senses, slowed time, out-of-body sensations or other features associated with near-death, despite not being in grave danger. Research shows that near-death experiences come in four types: emotional, cognitive, spiritual and religious experiences, and supernatural. Of the four, people often recall supernatural activity, particularly the feeling of detaching from a physical body.

About 76 percent of people report an out-of-body experience during a near-death experience. While some people may attribute this to a spiritual experience, this is actually a sensory deception caused by the brain, which scientists have successfully replicated in people who are asleep. Research has shown that direct electrical stimulation of a brain area normally inactive in REM sleep can provoke an out-of-body experience. “Like a flip of a switch, you can literally throw somebody out of their body and back into their body,” Nelson says.

[Related: CPR can save lives. Here’s how (and when) to do it.]

Often, though, people with cardiac arrest will recall near-death experiences. “About a quarter of people who suffer and survived cardiac arrest have memories about some aspect of near-death experience, Borjigin says. This is because people with cardiac arrest have decreasing blood pressure, she says. With the heart unable to pump properly, oxygen is unable to travel to the rest of the body, which is essential for every single cell in your body to survive. When a brain is alerted to a sudden decline in oxygen, your brain undergoes certain changes that contribute to the perceptual distortions that accompany a near-death experience. 

Electrical surges in the brain

Ten years ago, Borjigin and her team observed that rats in simulated cardiac arrest still had fully active brains even 30 seconds after their hearts stopped. What’s more, their brains increased in electrical activity. To confirm whether this happens in humans, Borjigin recently tested the brains of four people who were critically ill and removed from life support.

When these comatose patients were taken off their ventilators, they could not breathe on their own. But, using EEGs, Borjigin noticed two people showed a surge in gamma brainwaves as their bodies started shutting down. Gamma brainwaves are usually a sign of consciousness, because they are mostly active when someone is awake and alert. 

“We’ve shown the brain has a unique mechanism that deals with a lack of oxygen because oxygen is so essential for survival that even an acute loss massively activates the brain and could lead to a near-death experience,” Borjigin explains. 

The boost in gamma waves occurred in a brain area called the temporo-parieto-occipital (TPO) junction. This is responsible for blending information from our senses, including touch, motion, and vision, into our conscious selves. It’s impossible to know if the increased brain activity was related to any visions they may have had, because, sadly, the two patients died. But Borjigin suggests activation of this area suggests people may likely pick up sounds and understand language. “They might hear and perceive the conversation around them and form a visual image in their brain even when their eyes are closed.” 

Hidden consciousness

In one of the largest studies of near-death experiences, an international team of doctors has linked the surge in brain activity to what they called a hidden consciousness immediately following death. In the study, people who were brought back to life through CPR after cardiac arrest could recall memories and conversations while they were seemingly unconscious. 

Between May 2017 and March 2020, the team tracked 567 people who underwent a cardiac arrest. They used EEGs and cerebral oxygenation monitoring to measure electrical activity and brain oxygen levels during CPR. To study auditory and visual awareness, the team used a tablet showing one of 10 images on the screen, and five minutes after, it would play a recording of fruit names: pear, banana, and apple, for another five minutes. 

Only 53 people of the original 567 participants were successfully resuscitated. Initially, they showed no signs of brain activity and were considered dead. But during the CPR, the team noticed bursts of activity. These spikes included gamma waves and others: delta, theta, alpha, and beta waves—all electrical activity that signals consciousness. 

[Related: How your brain conjures dreams]

Twenty-eight of those 53 patients were cognitively capable of having an interview. Eleven people recalled being lucid during CPR, being aware of what was happening or showing perceptions of consciousness like an out-of-body experience. No one could recall the visual image but when asked to randomly name three fruit, one person correctly named all the fruits in the audio recording—though the authors note this could have been a random lucky guess. 

The study authors also included self-reports of 126 other survivors of cardiac arrests not involved in the study and what they remembered from almost dying. Common themes included the pain and pressure of chest compressions, hearing conversations from doctors, out-of-body experiences, and abstract dreams that had nothing to do with the medical event.

The findings debunk the idea that an oxygen-deprived brain stays alive for only five to ten minutes. They also raise the question whether doctors can save people already determined to be dead. “These patients were actually alive within, as seen in the positive waves on the EEG, but externally they were dead,” says Chinwe Ogedegbe, an emergency trauma center section chief and coauthor of the study. 

Beyond the brain’s resilience to the lack of oxygen, the authors propose an alternative “braking system” that could explain the distorted perceptions of consciousness. The brain normally filters and inhibits unneeded information when you’re awake. In this unconscious state, however, the braking system is gone, which could allow dormant brain pathways to activate and access a deeper realm of consciousness containing all of your memory, thoughts, and actions. “Instead of being hallucinatory, illusory or delusional, this appears to facilitate lucid understanding of new dimensions of reality,” the authors write in their paper.

Unfortunately, with only a small number of participants surviving their cardiac arrest, it’s unclear whether this altered consciousness is more visual or auditory. Ogedegbe is working to increase the number of participants in the next trial to 1,500. Doing so will give researchers a better idea of the type of brain activity that goes on when someone is at death’s door, and potentially provide comfort that their loved ones can sense them in their final moments.

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Despite having the critical and even miraculous ingredients to sustain life from microscopic viruses up to big blue whales, planet Earth likely has a future that spells some doom for most, if not all, species of mammals—including humans. A study published September 25 in the journal Nature Geosciences made the bold prediction that in about 250 million years, all of Earth’s major land masses will join together as one. When they do, it could make our planet one extremely hot and almost completely uninhabitable for mammals.

[Related: Mixing volcanic ash with meteorites may have jump-started life on Earth.]

“Widespread temperatures of between 40 to 50 degrees Celsius [104 to 122 degrees Fahrenheit], and even greater daily extremes, compounded by high levels of humidity would ultimately seal our fate,” study co-author and University of Bristol paleoclimatologist Alexander Farnsworth said in a statement. “Humans—along with many other species—would expire due to their inability to shed this heat through sweat, cooling their bodies.”

The models in this study predict that CO₂ levels would rise to between 410 parts per million and 816 parts per million in a few million years This is roughly the same as today’s level, which is already pushing the planet into dangerously hot water, or up to twice as high.

“They do explain quite nicely that it’s a combination of both those factors, kind of a double whammy situation,” geophysicist Ross Mitchell of the Chinese Academy of Sciences, who was not involved in the study, told Science magazine. “If there’s any disagreement I have with this paper, it’s that they’re more right than they thought they were.”

This prediction aligns well with Earth’s past periods of mass extinction and the volatile history of our planet. Here are some other times that mammalian and human life on Earth was almost completely wiped out.

The Pleistocene Ancestral Bottleneck

About 800,000 to 900,000 years ago, the population of human ancestors drastically dropped. A study published in August estimates that there were only about 1,280 breeding individuals alive during this transition between the early and middle Pleistocene. About 98.7 percent of the ancestral population was lost at the beginning of this ancestral bottleneck that lasted for roughly 117,000 years.

During this time, modern humans spread outside of the African continents and other early human species like Neanderthals began to go extinct. The Australian continent and the Americas also saw humans for the first time and the climate was generally cold. 

Some of the potential reasons behind this population drop are mostly related to extremes in climate. Temperatures changed, severe droughts persisted, and food sources may have dwindled as animals like mammoths, mastodons, and giant sloths went extinct. According to the study, an estimated 65.85 percent of current genetic diversity may have been lost due to this bottleneck.

[Related: We’re one step closer to identifying the first-ever mammals.]

The Great Dying

About 250 million years ago, massive volcanic eruptions triggered catastrophic climate changes that killed 80 to 90 percent of species on Earth. The Permian-Triassic mass extinction, or the “Great Dying,” paved the way for dinosaurs to dominate Earth, but was even worse than the Cretaceous–Paleogene extinction that wiped out the dinosaurs 66 million years ago.

According to a study published in May, saber-toothed creature called Inostrancevia filled a gap in southern Pangea’s ecosystem, when it was already devoid of top predators. Eventually, Inostrancevia also went extinct about 252 million years ago, as Earth’s species fought to gain a foothold on a changing planet. 

This example of how the past is prologue also bears a warning for our future, since the team says The Great Dying is the historical event that most closely parallels Earth’s current environmental crisis.

“Both involve global warming related to the release of greenhouse gasses, driven by volcanoes in the Permian and human actions currently,” study co-author museum curator and paleontologist Christian Kammerer told PopSci in May. “[They] represent a very rare case of rapid shifts between icehouse and hothouse Earth. So, the turmoil we observe in late Permian ecosystems, with whole sections of the food web being lost, represents a preview for our world if we don’t change things fast.”

The Ultimate Mammalian Survivor

Despite Earth constantly trying to kill us, life finds a way. Some of our very early ancestors potentially even shared a brief moment with Titanosaurs and the iconic Triceratops. These distant mammalian relatives also survived the Earth’s most famous mass extinction event: the Cretaceous-Paleogene (K-Pg) mass extinction that wiped out non-avian dinosaurs on a spring day about 66 million years ago.

[Related: This badger-like mammal may have died while trying to eat a dinosaur.]

A study published in June revealed that a Cretaceous origin for placental mammals, the diverse group that includes humans, dogs, and bats, briefly co-existed with dinosaurs. After an asteroid struck the Earth near Mexico’s Yucatán Peninsula, the devastation in its wake wiped out all of the non-avian dinosaurs and many mammals, such as a Madagascan rodent-looking animal named Vintana sertichi  that weighed up to 20 pounds Scientists have long debated if placental mammals were present with the dinosaurs before the Cretaceous-Paleogene (K-Pg) mass extinction, or if they only evolved after the dinosaurs died out. 

This study used statistical analysis that showed groups that include primates, rabbits and hares (Lagomorpha), and dogs and cats (Carnivora) evolved just before the K-Pg mass extinction and the impact that the modern lines of today’s placental mammals started to take shape after the asteroid hit. As with other mammals, they likely began to diversify once the dinosaurs were out of the picture.

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Most nutritionists advise people to “eat the rainbow” to balance their diet—think greens like kale, purples like eggplant, reds like tomatoes.  Consuming nutritious and naturally occuring orange foods like carrots packed with vitamin A, fiber, antioxidants, and pigments called carotenoids is a must to get a full and healthy spectrum. Carotenoids even got their name because they were first isolated from carrots.  But what is exactly behind the bright hue of some of our favorite carrots? Only three specific genes are required to give orange carrots their signature color, according to a study published September 28 in the journal Nature Plants.

[Related: Carrots were once a crucial tool in anti-Nazi propaganda.]

In the study, a team from North Carolina State University and the University of Wisconsin-Madison looked at the genetic blueprints of more than 600 varieties of carrots. Surprisingly, they found that these three required genes all need to be recessive, or turned off.

“Normally, to make some function, you need genes to be turned on,” study co-author and North Carolina State University horticultural scientist Massimo Iorizzo said in a statement.  “In the case of the orange carrot, the genes that regulate orange carotenoids—the precursor of vitamin A that have been shown to provide health benefits—need to be turned off,” Iorizzo said. 

In 2016, this team sequenced the carrot genome for the first time and also uncovered the gene involved in the pigmentation of yellow carrot. For this new study, they sequenced 630 carrot genomes as part of a continuing study on the history and domestication of the crunchy root veggie.

The team performed selective sweeps, or structural analyses among five different carrot groups. During these sweeps, they looked for areas of the genome that are heavily selected in certain groups. They found that many of the genes involved in flowering were under selection, primarily to delay the flowering process. This event causes the edible root that we eat called the taproot to turn woody and inedible. 

“We found many genes involved in flowering regulation that were selected in multiple populations in orange carrot[s], likely to adapt to different geographic regions,” said Iorizzo. 

Additionally, the study created a general timeline of carrot domestication and found more evidence that carrots were domesticated in the 9th or 10th century CE in western and central Asia. 

“Purple carrots were common in central Asia along with yellow carrots. Both were brought to Europe, but yellow carrots were more popular, likely due to their taste,” said Iorizzo.

[Related: WTF are purple carrots and where did they come from?]

In about the 15th or 16th century, orange carrots made their appearance in western Europe, potentially as the result of crossing a yellow carrot with a white one. The bright color and sweet flavor of orange carrots likely made it more popular than other varieties, so farmers continued selecting for them. In northern Europe, different types of orange carrots were developed in the 16th and 17th centuries and orange carrots of various shades can be seen in paintings from that area. They continued to grow in popularity as more understanding about the importance of alpha- and beta-carotenes and vitamin A in the diet for eye health progressed in the late 19th and early 20th centuries. 

The findings in this study shed more light on the traits that are important to improving carrots and could lead to better health benefits from the nutritious vegetable.

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One of the most enduring mysteries about our earliest ancestors and extinct human relatives is how they ate and procured enough food to sustain themselves millions of years ago. We believe that archery first arrived in Europe about 54,000 years ago and Neanderthals were cooking and eating crab about 90,000 years ago, but scavenging was likely necessary to get a truly hearty meal. A modeling study published September 28 in the journal Scientific Reports found that groups of hominins roughly 1.2 to 0.8 million years ago in southern Europe may have been able to compete with giant hyenas for carcasses of animals abandoned by larger predators like saber-toothed cats.

[Related: An ‘ancestral bottleneck’ took out nearly 99 percent of the human population 800,000 years ago.]

Earlier research has theorized that the number of carcasses abandoned by saber-toothed cats may have been enough to sustain some of southern Europe’s early hominin populations. However, it’s been unclear if competition from giant hyenas (Pachycrocuta brevirostris) would have limited hominin access to this food source. These extinct mongoose relatives were about 240 pounds–roughly the size of a lioness–and went extinct about 500,000 years ago. 

“There is a hot scientific debate about the role of scavenging as a relevant food procurement strategy for early humans,” paleontologist and study co-author Jesús Rodríguez from the National Research Center On Human Evolution (CENIEH) in Burgos, Spain tells PopSci. “Most of the debate is based on the interpretation of the scarce and fragmentary evidence provided by the archaeological record. Without denying that the archaeological evidence should be considered the strongest argument to solve the question, our intention was to provide elements to the debate from a different perspective.”

For this study, Rodríguez and co-author Ana Mateos looked at the Iberian Peninsula in the late-early Pleistocene era. They ran computer simulations to model competition for carrion–the flesh of dead animals–between hominins and giant hyenas in what is now Spain and Portugal. They simulated whether saber-toothed cats and the European jaguar could have left enough carrion behind to support both hyena and hominin populations—and how this may have been affected by the size of scavenging groups of hominins. 

They found that when hominins scavenged in groups of five or more, these groups could have been large enough to chase away giant hyenas. The hominin populations also exceeded giant hyena populations by the end of these simulations. However, when the hominins scavenged in very small groups, they could only survive to the end of the simulation when the predator density was high, which resulted in more carcasses to scavenge.  

[Related: Mysterious skull points to a possible new branch on human family tree.]

According to their simulations, the potential optimum group size for scavenging hominins was just over 10 individuals. This size was large enough to chase away saber-toothed cats and jaguars. However, groups of more than 13 individuals would have likely required more carcasses to sustain their energy expenditure. The authors caution that their simulations couldn’t specify this exact “just right” group size, since the numbers of hominins needed to chase away hyenas, saber-toothed cats, and jaguars were pre-determined and arbitrarily assigned.

“The simulations may not determine the exact value of the optimum, but show that it exists and depends on the number of hominins necessary to chase away the hyenas and of the size of the carcasses,” says Rodríguez.

Scavenged remains may have been an important source of meat and fat for hominins, especially in winter when plant resources were scarce. This team is working on simulating the opportunities hominins had for scavenging in different ecological scenarios in an effort to change a view that scavenging is marginal and that hunting is a more “advanced” and more “human” behavior than scavenging. 

“The word for scavenger in Spanish is ‘carroñero.’ It has a negative connotation, and is frequently used as an insult. We do not share that view,” says Rodríguez. “Scavengers play a very important role in ecosystems, as evidenced by the ecological literature in the last decades. We view scavenging as a product of the behavioral flexibility and cooperative abilities of the early hominins.”

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About 465 million years ago, a now extinct arthropod called a trilobite was eating its way across the present day Czech Republic. After it died, the passage of time actually preserved the plentiful contents of this specimen’s prehistoric guts. A team of paleontologists is using this full fossilized belly to learn more about the feeding habits and lifestyle of these common fossilized arthropods. The findings are detailed in a study published September 27 in the journal Nature.

[Related: Trilobites may have jousted with head ‘tridents’ to win mates.]

More than 20,000 species of trilobite lived during the early Cambrian to the end-Permian period roughly 541 to 252 million years ago. They are some of the most common fossil specimens from this time period, yet paleontologists do not know much about their feeding habits since gut contents usually disappear over time, and until recently there were no known fossil specimens with them intact.

In the study, a team from institutions in Sweden and the Czech Republic examined a fossil specimen of Bohemolichas incola first uncovered near Prague over 100 years ago. Study co-author and paleontologist Petr Kraft from Charles University in Prague had long suspected that this specimen may have a gut full of food intact, but did not have a suitable technique to look inside the trilobite’s innards. Study co-authors and paleontologists Valéria Vaskaninova and Per Ahlberg from Uppsala University in Sweden suggested using a synchrotron in one of their fossil scanning sessions. This machine is a large electron accelerator that produces powerful laser-like x-rays to take high-quality scans of the fossil

“The results were fantastic, showing all the gut contents in detail so that we could identify what the trilobite had been eating,” Ahlberg tells PopSci. “Remains of ostracods (small shell-bearing crustaceans, still around today), hyoliths (extinct cone-shaped animals of uncertain affinities) and stylophorans (extinct echinoderms that look like little armor-plated electric guitars). These are all kinds of animals that lived in the local environment.”

The team believes that Bohemolichas incola was likely an opportunistic scavenger. It also was potentially a light crusher and a chance feeder, which means that it ate both dead or living animals, which either disintegrated easily or were actually small enough to be swallowed whole. However, after this particular Bohemolichas incola died, the circle of life continued and the scavenger became the scavenged. Vertical tracks of other scavengers were found on the specimen. These unknown creatures burrowed into this trilobite’s carcass and targeted its soft tissue, but avoided its gut. Staying away from the gut implies that there were some noxious conditions inside Bohemolichas incola’s digestive system and potentially ongoing enzymatic activity.

[Related: These ancient trilobites are forever frozen in a conga line.]

“We were able to draw conclusions about the chemical environment inside the gut of the living trilobite. The shell fragments on the gut have not been etched by stomach acids, and this shows that the gut pH must have been close to neutral, similar to the condition in modern crabs and horseshoe crabs,” says Ahlberg. “This may indeed be a very ancient shared characteristic of trilobites and these modern arthropods.”

Future studies into trilobites could use similar techniques to look for more gut fills. Since this group is a very diverse group of animals, it can’t be assumed that this particular species is representative of the feeding habits for all. 

“This project shows how cutting-edge technology can come together with really old museum specimens. The trilobite was collected in 1908, and has been in a museum ever since, but it is only now that we have the technology to unlock its secrets,” says Ahlberg. “This illustrates not only the rapid technological progress of our time, but also the importance of well-maintained museum collections.”

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The natural circles that pop up on the soil in the planet’s arid regions are an enduring scientific debate and mystery. These “fairy circles” are circular patterns of bare soil surrounded by plants and vegetation. Until very recently, the unique phenomena have only been described in the vast Namib desert and the Australian outback. While their origins and distribution are hotly debated, a study with satellite imagery published on September 25 in the journal Proceedings of the National Academy of Sciences (PNAS) indicates that fairy circles may be more common than once realized. They are potentially found in 15 countries across three continents and in 263 different sites. 

[Related: A new study explains the origin of mysterious ‘fairy circles’ in the desert.]

These soil shapes occur in arid areas of the Earth, where nutrients and water are generally scarce. Their signature circular pattern and hexagonal shape is believed to be the best way that the plants have found to survive in that landscape. Ecologist Ken Tinsly observed the circles in Namibia in 1971, and the story goes that he borrowed the name fairy circles from a naturally occurring ring of mushrooms that are generally found in Europe.

By 2017, Australian researchers found the debated western desert fairy circles, and proposed that the mechanisms of biological self-organization and pattern formation proposed by mathematician Alan Turing were behind them. In the same year, Aboriginal knowledge linked those fairy circles to a species of termites. This “termite theory” of fairy circle origin continues to be a focus of research—a team from the University of Hamburg in Germany published a study seeming to confirm that termites are behind these circles in July.

In this new study, a team of researchers from Spain used artificial intelligence-based models to look at the fairy circles from Australia and Namibia and directed it to look for similar patterns. The AI scoured the images for months and expanded the areas where these fairy circles could exist. These locations include the circles in Namibia, Western Australia, the western Sahara Desert, the Sahel region that separates the African savanna from the Sahara Desert, the Horn of Africa to the East, the island of Madagascar, southwestern Asia, and Central Australia.

The team then crossed-checked the results of the AI system with a different AI program trained to study the environments and ecology of arid areas to find out what factors govern the appearance of these circular patterns. 

“Our study provides evidence that fairy-circle[s] are far more common than previously thought, which has allowed us, for the first time, to globally understand the factors affecting their distribution,” study co-author and Institute of Natural Resources and Agrobiology of Seville soil ecologist Manuel Delgado Baquerizo said in a statement. 

[Related: The scientific explanation behind underwater ‘Fairy Circles.’]

According to the team, these circles generally appear in arid regions where the soil is mainly sandy, there is water scarcity, annual rainfall is between 4 to 12 inches, and low nutrient continent in the soil.

“Analyzing their effects on the functioning of ecosystems and discovering the environmental factors that determine their distribution is essential to better understand the causes of the formation of these vegetation patterns and their ecological importance,” study co-author and  University of Alicante data scientist Emilio Guirado said in a statement. 

More research is needed to determine the role of insects like termites in fairy circle formation, but Guirado told El País that “their global importance is low,” and that they may play an important role in local cases like those in Namibia, “but there are other factors that are even more important.”

The images are now included in a global atlas of fairy circles and a database that could help determine if these patterns demonstrate resilience to climate change. 

“We hope that the unpublished data will be useful for those interested in comparing the dynamic behavior of these patterns with others present in arid areas around the world,” said Guirado.

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In nature, patterns of chemical interactions between two different substances are believed to govern the designs our eyes see—for example, a zebra’s stripes. These stripey designs are governed by a mathematical basis that is potentially overseeing another completely unrelated thing—the wavy patterns formed by sperm’s motion. According to a study published September 27 in the journal Nature Communications, the same mathematical theory could traverse both.

[Related: Monarch butterflies’ signature color patterns could inspire better drone design.]

To understand the connection, we need to go back more than 70 years. The wavy undulations of a sperm’s tail—or flagella—make striped patterns in space-time. These patterns potentially follow the same template proposed by mathematician Alan Turing, one of the most famous scientists of the 20th century. Turing is most well-known for helping crack the enigma code during World War II and ushering in a new age of computer science, but he also developed a theory informally called the reaction-diffusion theory for pattern formation. This 1952 theory predicted that recognizable patterns in nature may appear spontaneously when chemicals within the objects or organisms diffuse and then react together.

While this theory hasn’t been well proven by experimental evidence, Turing’s theory sparked more research into using reaction-diffusion mathematics as a way to understand natural patterns. These so-called Turing patterns are believed to govern leopard spots, whorls of seeds in sunflower heads, and even patterns of sand on the beach. 

In this new study, a team from the University of Bristol in England used Turing patterns as a way to look at the movement of sperm’s flagella and vibrating hair-like cells called cilia. 

“Live spontaneous motion of flagella and cilia is observed everywhere in nature, but little is known about how they are orchestrated,” study co-author and mathematician Hermes Gadêlha said in a statement. “They are critical in health and disease, reproduction, evolution, and survivorship of almost every aquatic microorganism [on] earth.”

Flagellar undulations are believed to make stripe patterns in space-time, in the form of the waves that travel along the tail to drive the sperm forward when it is in fluid. To look deeper, Gadêlha and his team used mathematical modeling, simulations, and data fitting to show that wavy flagellar movement can actually arise spontaneously without the influence of the fluid in their environment. According to the team, this is mathematically equivalent to Turing’s reaction-diffusion system that was first proposed for chemical patterns over 70 years ago.

For the swimming sperm, chemical reactions of molecular motors power its tail and the bending movement diffuses along the tail in waves. The fluid itself is playing a very minor role on how the tail moves.

[Related: The genes behind your fingerprints just got weirder.]

“We show that this mathematical ‘recipe’ is followed by two very distant species—bull sperm and Chlamydomonas (a green algae that is used as a model organism across science), suggesting that nature replicates similar solutions,” said Gadêlha. “Traveling waves emerge spontaneously even when the flagellum is uninfluenced by the surrounding fluid. This means that the flagellum has a fool-proof mechanism to enable swimming in low viscosity environments, which would otherwise be impossible for aquatic species. It is the first time that model simulations compare well with experimental data.”

The findings of this study could help understand fertility issues associated with abnormal flagellar motion, diseases caused by ineffective cilia, and be applied to robotics. Other models in nature may exist that could provide further experimental proof of Turing’s template, but more research is needed.  

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Scientists in Thailand have discovered a new species of tarantula with a very unique blue hue. The tarantula is named Chilobrachys natanicharum and is also called the electric blue tarantula. The findings were described in a study published September 18 in the journal ZooKeys 

[Related: Before spider mites mate, one of them gets their skin removed.]

The new colorful arachnid was discovered in southern Thailand’s Phang-Nga province. It follows the identification of another new species of tarantula called Taksinus bambus, or the bamboo culm tarantula.

“In 2022, the bamboo culm tarantula was discovered, marking the first known instance of a tarantula species living inside bamboo stalks,” study co-author and Khon Kaen University entomologist Narin Chomphuphuang said in a statement. “Thanks to this discovery, we were inspired to rejoin the team for a fantastic expedition, during which we encountered a captivating new species of electric blue tarantula.”

The team that found the first not-so-blue bamboo culm tarantula included a local wildlife YouTuber named JoCho Sippawat. This year, Chomphuphuang joined up with Sippawat for a surveying expedition in the province to learn more about tarantula diversity and distribution. They identified this new species by this very distinctive coloration during the expedition.

“The first specimen we found was on a tree in the mangrove forest. These tarantulas inhabit hollow trees, and the difficulty of catching an electric-blue tarantula lies in the need to climb a tree and lure it out of a complex of hollows amid humid and slippery conditions,” Narin said. “During our expedition, we walked in the evening and at night during low tide, managing to collect only two of them.”

The color blue is very rare in nature. It can even exist in other animals that aren’t usually this color, including the blue lobsters that have recently been found in Massachusetts and France. Some animals also evolved wild colors including blues, yellows, and reds to appear poisonous to try and keep other animals from eating them.  

In order for an organism to appear blue, it must absorb very small amounts of energy while reflecting high-energy blue light. Since penetrating molecules that are capable of absorbing this energy is a complex process, the color blue is less common than other colors in the natural world. 

According to the study, the secret behind the electric blue tarantula’s wild color comes from the unique structure of their hair and not from a presence of blue pigment. Their hair incorporates nanostructures that manipulate the light shining on it to create the blue appearance. Their hair can also display a more violet hue depending on the light, which creates an iridescent effect. 

[Related: Blue-throated macaws are making a slow, but hopeful, comeback.]

This species was previously found on the commercial tarantula market, but there hadn’t been any documentation describing its natural habitat or unique features. 

“The electric blue tarantula demonstrates remarkable adaptability. These tarantulas can thrive in arboreal as well as terrestrial burrows in evergreen forests,” Narin said. “However, when it comes to mangrove forests, their habitat is restricted to residing inside tree hollows due to the influence of tides.”

To name the new species, the authors conducted an auction campaign and the scientific name of Chilobrachys natanicharum was selected. It is named after executives Natakorn and Nichada Changrew of Nichada Properties Co., Ltd., Thailand and the proceeds of the auction were donated to support the education of Indigenous Lahu children in Thailand and for cancer patients in need of money for treatment.

The authors say that this discovery points to the continued importance of taxonomy as a basic aspect of research and conservation. It also highlights the need to protect mangrove forests from continued deforestation, as the electric blue tarantula is also one of the world’s rarest tarantulas. 

“This raises a critical question: Are we unintentionally contributing to the destruction of their natural habitats, pushing these unique creatures out of their homes?” the researchers ask in their conclusion.

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As their giant petals open, the blooming of flowers in the genus Rafflesia brings with them an overwhelming odor mimics the smell of rotting flesh. While their pungent stink might keep humans away and attract flies, a study published September 19 in the journal Plants People Planet found that 67 percent of the habitats for these notorious plants is at risk of destruction. 

[Related: Corpse flowers across the country are swapping pollen to stay stinky.]

Rafflesia are the largest flowers in the world and have been a botanical enigma for centuries. In addition to their infamous stink, corpse flowers are actually a parasite that infects vines in the tropical jungles of Thailand, Indonesia, Malaysia, Brunei, and the Philippines. It remains hidden from sight for the majority of its lifecycle, existing as a system of tiny thread-like filaments that invades its host. At unpredictable intervals, the parasite produces a cabbage-like bud that will break through a vine’s bark and eventually form a giant, five-lobed flower, up to 3.2 feet across. The flower produces its signature rotten meat smell to attract pollinating flies.

This elusive lifecycle and ability to remain hidden makes them very poorly understood by botanists, and new species are still being discovered by botanists. With such an elusive lifecycle, Rafflesia remains poorly understood, and new species are still being recorded. 

In the study, an international group of researchers established the first coordinated global network to assess the threats facing Rafflesia. This network found most of the 42 known species of Rafflesia are severely threatened, but only one is listed on the IUCN’s Red List of Threatened Species. This leaves many unprotected by regional or national conservation strategies. The scientists classified 25 species as Critically Endangered and 15 as Endangered, according to the IUCN’s criteria for classification. 

Chris Thorogood of the University of Oxford Botanic Garden in England co-authored the study and an upcoming book on the team’s years devoted to documenting these plants. In a statement, Thorogood said that this work, “Highlights how the global conservation efforts geared towards plants–however iconic–have lagged behind those of animals. We urgently need a joined-up, cross-regional approach to save some of the world’s most remarkable flowers, most of which are now on the brink of being lost.”

Additionally, Rafflesia species often have very restricted geographical distributions, making them particularly vulnerable to habitat destruction. Many of the remaining populations of corpse flowers have only a few individuals in unprotected areas that are at risk of being converted for agricultural use, according to the study. While these and other similarly smelly flowers famously exist in some botanical gardens, these institutions have had limited success in breeding them, making habitat conservation an urgent priority.

[Related: These parasitic plants force their victims to make them dinner.]

The four-point action plan proposed by the team for local governments, research centers, and conservation organizations  includes greater habitat protections, better understanding of the full diversity of the Rafflesia that exists to better inform policy making, developing better methods to breed them outside their native habitat, and introducing new ecotourism initiatives to engage local communities in Rafflesia conservation.

The study also highlighted some valuable success stories that may offer important insights for Rafflesia conservation elsewhere, including the Bogor Botanic Garden in West Java, Indonesia, that saw a series of successful blooming events and villagers in West Sumatra benefitting from Rafflesia ecotourism by forming “pokdarwis” or tourism awareness groups linked to social media.

“Indigenous peoples are some of the best guardians of our forests, and Rafflesia conservation programmes are far more likely to be successful if they engage local communities,” Adriane Tobias, a study co-author and forester from the University of the Philippines Los Baños, said in a statement. “Rafflesia has the potential to be a new icon for conservation in the Asian tropics.”

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Marine virologists have found a novel virus living in the incredibly deep and dark Mariana Trench, more than 29,000 feet under the ocean’s surface. The virus is the deepest known isolated bacteriophage—viruses that infect and replicate inside bacteria—ever found, according to a study published September 20 in the journal Microbiology Spectrum.

[Related: Meet the marine geologist mapping the deepest point on Earth.]

The enormous trench in the western Pacific Ocean near Guam is over 36,000 feet deep at its lowest depth and is part of the hadal zone. This zone is named for Hades, the Greek god of the underworld, for its deep trenches and high pressures. The buildup of carbon along the base of the hadal zone’s trenches may even help regulate the Earth’s climate and carbon cycle. Even in its intense pressures and extreme cold and darkness, life continues to find a way. Scientists have discovered fish, shrimp, and lots of microbes lurking there. That life includes regulators to keep the living things in check. 

“Wherever there’s life, you can bet there are regulators at work. Viruses, in this case,” study co-author and Ocean University of China marine virologist Min Wang said in a statement.

This new phage works by infecting bacteria in the phylum Halomonas, which are commonly found in sediments deep seas and the geyser-like openings on the seafloor that release streams of hot water called hydrothermal vents.

In their study, Wang and an international group of researchers describe the new virus identified as vB_HmeY_H4907. The virus was brought up in sediment from a depth of about 5.5 miles or more than 29,000 feet deep and is classified as a bacteriophage. Also called phage, they infect and replicate inside bacteria and are believed to be the most abundant life forms on Earth.

“To our best knowledge, this is the deepest known isolated phage in the global ocean,” said Wang.

According to Wang, the analysis of the viral genetic material points to the existence of a previously unknown viral family living in the deep ocean and some new insights into the evolution, genetic diversity, genomic features of deep-sea phages and how they interact with their hosts. 

Previously, this team has used metagenomic analysis to study the viruses that infect bacteria in the order Oceanospirallales. This order includes Halomonas, the phylum that this newly discovered virus infects. In this new study, the team searched for viruses in bacterial strains isolated by marine virologist Yu-Zhong Zhang, also from the Ocean University of China. 

[Reading: A deep sea mining zone in the remote Pacific is also a goldmine of unique species.]

The genomic analysis of the new virus suggests that it has a similar structure to its host and is widely distributed in the ocean. It is also lysogenic, meaning it invades and replicates inside its host, but typically does not kill the bacterial cell. The virus’s genetic material is then copied and passed on as the cells divide.

The discovery points to some new questions focused on the survival strategies that viruses living in harsh and generally secluded environments like the hadal zone trenches use and how they co-evolve with their hosts. Future studies also will aim to investigate the molecular machinery driving interactions between deep-sea viruses and their hosts. 

According to Wang, discovering more new viruses in extreme places, “would contribute to broadening our comprehension of the virosphere. Extreme environments offer optimal prospects for unearthing novel viruses.”

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Is Earth primarily a planet of life, a world stewarded by the animals, plants, bacteria, and everything else that lives here? Or, is it a planet dominated by human creations? Certainly, we’ve reshaped our home in many ways—from pumping greenhouse gases into the atmosphere to literally redrawing coastlines. But by one measure, biology wins without a contest.

 In an opinion piece published in the journal Life on August 31, astronomers and astrobiologists estimated the amount of information transmitted by a massive class of organisms and technology for communication. Their results are clear: Earth’s biosphere churns out far more information than the internet has in its 30-year history. “This indicates that, for all the rapid progress achieved by humans, nature is still far more remarkable in terms of its complexity,” says Manasvi Lingam, an astrobiologist at the Florida Institute of Technology and one of the paper’s authors.

[Related: Inside the lab that’s growing mushroom computers]

But that could change in the very near future. Lingam and his colleagues say that, if the internet keeps growing at its current voracious rate, it will eclipse the data that comes out of the biosphere in less than a century. This could help us hone our search for intelligent life on other planets by telling us what type of information we should seek.

To represent information from technology, the authors focused on the amount of data transferred through the internet, which far outweighs any other form of human communication. Each second, the internet carries about 40 terabytes of information. They then compared it to the volume of information flowing through Earth’s biosphere. We might not think of the natural world as a realm of big data, but living things have their own ways of communicating. “To my way of thought, one of the reasons—although not the only one—underpinning the complexity of the biosphere is the massive amount of information flow associated with it,” Lingam says.

Bird calls, whale song, and pheromones are all forms of communication, to be sure. But Lingam and his colleagues focused on the information that individual cells transmit—often in the form of molecules that other cells pick up and respond accordingly, such as producing particular proteins. The authors specifically focused on the 100 octillion single-celled prokaryotes that make up the majority of our planet’s biomass. 

“That is fairly representative of most life on Earth,” says Andrew Rushby, an astrobiologist at Birkbeck, University of London, who was not an author of the paper. “Just a green slime clinging to the surface of the planet. With a couple of primates running around on it, occasionally.”

Now, picture the reverse. For decades, scientists and military experts have sought out signatures of extraterrestrials in whatever form it may take. Astronomers have traditionally focused on the energy that a civilization of intelligent life might use—but earlier this year, one group crunched the numbers to determine if aliens in a nearby star system could pick up the leakage from mobile phone towers. (The answer is probably not, at least with LTE networks and technology like today’s radio telescopes.)

On the flip side, we don’t totally have the observational capabilities to home in on extraterrestrial life yet. “I don’t think there’s any way that we could detect the kind of predictions and findings that [Lingam and his coauthors] have quantified here,” Rushby says. “How can we remotely determine this kind of information capacity, or this information transfer rate? We’re probably not at the stage where we could do that.”

But Rushby thinks the study is an interesting next step in a trend. Astrobiologists—certainly those searching for extraterrestrial life—are increasingly thinking about the types and volume of information that different forms of life carries. “There does seem to be this information ‘revolution,’” he says, “where we’re thinking about life in a slightly different way.” In the end, we might learn that there’s more harmony between the communication networks nature has built and computers.

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There’s a recurring mystery surrounding early human migration: Exactly when did Homo sapiens make their way from Africa into Europe and Asia? It’s possible that a period of warmer temperatures could have contributed to this flow of people into Eurasia, according to a study published September 22 in the journal Science Advances. Warmer temperatures and more humidity may have helped the forests in the region grow and expand north into present-day Siberia. The theory hinges on the presence of pollen in the region’s sediment record. The scourge of modern day spring allergy sufferers could have laid the groundwork for our very distant ancestors’ migration into Eurasia.  

[Related: Humans and Neanderthals could have lived together even earlier than we thought.]

This movement could have begun in three waves into Eurasia about 54,000 years ago. It is also likely that both warm and cold climates would have played a role in this travel. The Pleistocene Epoch is known for huge climatic shifts, including the formation of the massive ice sheets and glaciers that would eventually forge and shape many of the landforms we see on Earth today. 

To piece together what the climate could have looked like during a possible warm period about 45,000 to 50,000 years ago, researchers working on the study created a record of the vegetation and pollen from the Pleistocene found around Lake Baikal in present-day Siberian region of Russia with the oldest archeological traces of Homo sapiens in the area. 

Sediment cores were used to extract data for a pollen timeline, and the study suggests that the dispersal of humans occurred during some of the highest temperatures and highest humidity of the late Pleistocene. The presence of more ancient pollen, and thus plant life, in the record shows evidence that coniferous forests and grasslands may have spread further throughout the region and could support foraging for food and hunting by humans. According to study author and University of Kansas anthropologist Ted Goebel, the environmental data combined with archeological evidence tell a new story of the area. 

“This contradicts some recent archaeological perspectives in Europe. The key factor here is accurate dating, not just of human fossils and animal bones associated with the archaeology of these people, but also of environmental records, including from pollen,” Goebel said in a statement. “What we have presented is a robust chronology of environmental changes in Lake Baikal during this time period, complemented by a well-dated archaeological record of Homo sapiens’ presence in the region.”

Goebel worked with teams from three institutions in Japan, including Masami Izuho of Tokyo Metropolitan University. During the pollen analysis, the team found some potential connections between the pollen data and the archeological record of early human migration into the region. The early modern humans of this period were making stone tools on slender blands and using bones, antlers, and even ivory to craft the tools. 

“There is one human fossil from Siberia, although not from Lake Baikal but farther west, at a place called Ust’-Ishim,” Goebel said. “Morphologically, it is human, but more importantly, it’s exceptionally well-preserved. It has been directly radiocarbon-dated and has yielded ancient DNA, confirming it as a representative of modern Homo sapiens, distinct from Neanderthals or Denisovans, or other pre-modern archaic humans.”

[Related: World’s oldest known wooden structure pre-dates our species.]

It’s possible that the earliest humans in the area likely would have lived in extended nuclear families, but it is difficult to say with certainty since so much archeological evidence has degraded over time. Ust’-Ishim in Siberia provides the earliest known evidence of fully modern humans coexisting with other extinct human species in the area, but the find was an “isolated discovery,” according to the team.

“We lack information about its archaeological context, whether it was part of a settlement or simply a solitary bone washed downstream,” said Goebel. “Consequently, linking that single individual to the archaeological sites in the Baikal region is tenuous—do they represent the same population? We think so, but definitely need more evidence.”

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Jellyfish are an undeniable evolutionary success story, surviving at least 500 million years in Earth’s oceans. They are even poised to handle climate change very well in some areas of the world, all without a centralized brain like most animals. Despite this lack of a central brain, trained Caribbean box jellyfish can potentially remember their past experiences the way that flies, mice, and humans do, and learn to spot and dodge previously encountered obstacles in a tank. The findings are reported in a study published on September 22 in the journal Current Biology.

[Related: Jellyfish may have been roaming the seas for at least 500 million years.]

This species of jellyfish is ubiquitous in the waters of the Caribbean Sea and the central Indo-Pacific Ocean, but are generally just about a half inch in diameter. Box jellyfish like these are members of a class of jellyfish that are known for being among the most poisonous animals in the world and their stings can cause paralysis and even death in extreme cases. 

To keep up their stinging and navigate their watery world, jellyfish don’t have a centralized brain like most members of the animal kingdom. They have four parallel brain-like structures with roughly 1,000 nerve cells in each. By comparison, a human brain has approximately 100 billion nerve cells. Caribbean box jellyfish are equipped with a complex visual system of 24 eyes embedded into their bell-shaped body. They use this unique vision to steer through the murky waters of mangrove swamps, looking for prey and diving under underwater tree roots. 

“It was once presumed that jellyfish can only manage the simplest forms of learning, including habituation–i.e., the ability to get used to a certain stimulation, such as a constant sound or constant touch,” study co-author and University of Copenhagen neurobiologist Anders Garm said in a statement. “Now, we see that jellyfish have a much more refined ability to learn, and that they can actually learn from their mistakes. And in doing so, modify their behavior.”

In this study, the team used a round tank outfitted with gray and white stripes to mimic the jellyfish’s natural habitat. The gray stripes were mimicking mangrove roots that would appear to be distant at the start of the experiment. For 7.5 minutes, the team observed the jellyfish in the tank. Initially, the jelly swam close to these seemingly far away stripes and bumped into them frequently. However, by the end of the experiment, the jelly increased its average distance to the wall by roughly 50 percent, quadrupled the number of successful pivots to avoid collision with the fake tree, and cut its contact with the wall by half. 

The findings suggest that jellyfish can learn from experience and could acquire the ability to avoid obstacles through a process called associative learning. In this process, organisms form mental connections between sensory stimulations and behaviors. 

“Learning is the pinnacle [of] performance for nervous systems,” Jan Bielecki, a co-author of the study and a neuroscientist at Kiel University in Germany, said in a statement.

Bielecki added that in order to teach jellyfish a new trick, “it’s best to leverage its natural behaviors, something that makes sense to the animal, so it reaches its full potential.”

[Related: Italian chefs are cooking up a solution to booming jellyfish populations.]

The team then looked into pinpointing the underlying process of jellyfish’s associative learning by isolating the animal’s visual sensory centers called rhopalia. Each rhopalia houses six eyes that control the jellyfish’s pulsing motion. This motion spikes in frequency when the jelly swerves away from an obstacle. 

They showed the stationary rhopalium moving gray bars to mimic how the jelly approaches objects and the rhopalium did not respond to light gray bars, seemingly interpreting the bars as distant. The researchers then trained the rhopalium with some weak electric stimulations that mimicked the mechanical stimuli that occur when colliding with an object. Following the electric stimulation, the rhopalium started to generate obstacle-dodging signals in response to the light gray bars as they got closer. 

The findings from this stage of the experiment showed that combining visual and mechanical stimuli is necessary for associative learning in jellyfish and that the rhopalium is likely serving as the animal’s learning center.

“For fundamental neuroscience, this is pretty big news. It provides a new perspective on what can be done with a simple nervous system,” said Garm. “This suggests that advanced learning may have been one of the most important evolutionary benefits of the nervous system from the very beginning.”

The team plans to do a deeper dive into the cellular interactions of jellyfish nervous systems to tease apart the process of memory formation and also hope to understand how the mechanical sensor in the jellyfish’s body works to paint a more complete picture of its associative learning.

“It’s surprising how fast these animals learn; it’s about the same pace as advanced animals are doing,” says Garm. “Even the simplest nervous system seems to be able to do advanced learning, and this might turn out to be an extremely fundamental cellular mechanism invented at the dawn of the evolution nervous system.”

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Earlier this year, the French bulldog replaced the Labrador retriever as the most popular pet dog in the United States. Flat-faced or brachycephalic dogs continue to be a favorite despite their health problems. These include breathing issues like Brachycephalic Obstructive Airway Syndrome (BOAS), an increased risk of heat stroke, and multiple eye issues stemming from aesthetic-based genetic engineering and extreme breeding. In response to these health issues, the Netherlands has banned their breeding on ethical grounds, and the British Veterinary Association has urged people to not buy flat-faced breeds.

[Related: How breeding dogs for certain traits may have altered their brains.]

Cognitive ethologist and behavior biologist Eötvös Loránd University in Hungary Dorottya Júlia Ujfalussy and her team are working on understanding a “paradox phenomenon,” where the number of these flat faced pets continues to increase, despite their known health and longevity issues.

“One reason for choosing a flat-faced pet may be the child-like appearance, however, owner reports suggest that behavior is also involved. We are trying to pinpoint the behavior traits that set these breeds apart from breeds with more healthy head shapes,” Ujfalussy tells PopSci.

In a small study published September 21 in the journal Scientific Reports, Ujfalussy and her team found that these breeds are more likely to look at humans longer and display traits that appear “helpless” and more infant-like to humans. The team assessed the behavior of 15 English bulldogs and 15 French bulldogs compared to the behavior of 13 Hungarian mudis. Mudis are herding dogs with a mid-length muzzle and do not have the bulldogs’ squished face. 

The dogs had to try and open three boxes to retrieve a piece of food. The boxes had different opening techniques that varied in difficulty and they were presented to all of the dogs in a random order. The dogs also saw one of the researchers put a piece of sausage into a box and were then given two minutes to open the box. The team and dog’s owner stood behind the dog and out of direct sight during the experiment. 

English and French bulldogs successfully opened the box 93 percent less often than the mudis did. The successful mudis were also faster than the bulldogs who opened the boxes. By the time one minute had gone by, roughly 90 percent of mudis had opened the box, compared to about 50 percent of the bulldogs. However, the bulldogs were 4.16 and 4.49 times as likely to look back at their people than mudis.

“The most surprising was the extent of the helplessness, lack of success and visual orientation of dogs to the owners,” Ujfalussy says. “It seemed like they were depending on their humans to solve problems for them much more than your typical family dogs.”

The team believes that these findings show that short-faced dogs seek out humans when faced with problems more frequently, which may promote a stronger social relationship between the owners and their dogs due to this perception of helplessness. 

[Related: Dogs and wolves remember where you hide their food.]

The study could not establish whether flat-faced dogs are actually genetically predisposed to look more dependent on humans than other dog breeds or whether  owners’ attitudes towards flat-faced dogs encourages dependent behavior. The team is working to continue to study these behavior characteristics.

“We would like to raise awareness of this ‘flat-faced’ paradox in the hope that people make more conscious choices of pets, not relying on their instincts and falling for the ‘cute looks’ and dependent (helpless) behavior that reminds them of human children,” says Ujfalussy.

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