Biology

Welcome to “necroprinting”—3D printer nozzle made from mosquito’s proboscis

3D printing, Biology, Biomechanics, materials science, mosquitos, printing, Science / Mike M. / December 4, 2025

“To integrate the proboscis, we first removed it from an already euthanized mosquito under a microscope,” Cao explains. Then the proboscis/nozzle was aligned with the outlet of the plastic tip. Finally, the proboscis and the tip were bonded with UV-curable resin.

The necroprinter achieved a resolution ranging from 18 to 22 microns, which was two times smaller than the printers using the smallest commercially available metal dispensing tips. The first print tests included honeycomb structures measuring 600 microns, a microscale maple leaf, and scaffolds for cells.

But there were still areas in which human-made technology managed to beat Mother Nature.

Glass and pressure

The first issue with mosquito nozzles was their relatively low resistance to internal pressure. “It was impressive but still too low to accommodate some high viscosity inks,” Cao said.

These inks, which look more like a paste than a typical fluid, hold shape better, which translates into more geometrically accurate models that do not slump or spread under their own weight. This was a problem that Cao’s test prints experienced to an extent.

But this wasn’t the only area where human-made technology managed to beat nature. While mosquito nozzles could outperform plastic or metal alternatives in precision, they could not outperform glass dispensing tips, which can print lines below one micron across and withstand significantly higher pressures.

The researchers already have some ideas about how to bridge at least a part of this gap, though. “One possible solution is to use mosquito proboscis as the core and coat it with ceramic layers to provide much higher strength,” Cao said. And if the pressure problem is solved, the 18–22 microns resolution should be good enough for plenty of things.

Cao thinks that in the future, printers like this could be used to print scaffolds for living cells or microscopic electronic components. The idea is to replace expensive, traditional 3D printing nozzles with more affordable organic counterparts. The key advantages of mosquito nozzles, he says, are low cost and ubiquity.

Mosquitoes live almost everywhere on Earth and are easy to rear. The team estimates that organic 3D printing nozzles made from mosquito proboscises should cost around 80 cents; the glass and metal alternatives, the researchers state in the paper, cost between 32 and 100 times more.

“We already started doing more research on mosquitoes themselves and hope to develop more engineering solutions, not only to leverage their deceased bodies but also to solve practical problems they cause,” Cao said.

Science Advances, 2025. DOI: 10.1126/sciadv.adw9953

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Humans in southern Africa were an isolated population until recently

africa, Biology, evolution, Genetics, Genomics, human evolution, Science / Tim Belzer / December 3, 2025

Collectively, the genetic variants in this population are outside the range of previously described human diversity. That’s despite the fact that the present-day southern African hunter-gatherer populations are largely derived from southern African ancestors.

What’s distinct?

Estimates of the timing of when this ancient south African population branched off from any modern-day populations place the split at over 200,000 years ago, or roughly around the origin of modern humans themselves. But this wasn’t some odd, isolated group; estimates of population size based on the frequency of genetic variation suggest it was substantial.

Instead, the researchers suggest that climate and geography kept the group separate from other African populations and that southern Africa may have served as a climate refuge, providing a safe area from which modern humans could expand out to the rest of the continent when conditions were favorable. That’s consistent with the finding that some of the ancient populations in eastern and western Africa contain some southern African variants by around 5,000 years ago.

As far as genetic traits are concerned, the population looked like pretty much everyone else present at the time: brown eyes, high skin pigmentation, and no lactose tolerance. None of the older individuals had genetic resistance to malaria or sleeping sickness that are found in modern populations. In terms of changes that affect proteins, the most common are found in genes involved in immune function, a pattern that’s seen in many other human populations. More unusually, genes that affect kidney function also show a lot of variation.

So there’s nothing especially distinctive or modern apparent in this population, especially not in comparison to any other populations we know of in Africa at the same time. But they are unusual in that they suggest there was a large, stable, and isolated group from other populations present in Africa at the time. Over time, we’ll probably get additional evidence that fits this population into a coherent picture of human evolution. But for now, its presence is a bit of an enigma, given how often other populations intermingled in our past.

Nature, 2025. DOI: 10.1038/s41586-025-09811-4 (About DOIs).

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Research roundup: 6 cool stories we almost missed

animals, Biology, chemistry, fermentation, microbiology, Physics, psychology, robotics, Science, social networks / Rejus Almole / December 1, 2025

The assassination of a Hungarian duke, why woodpeckers grunt when they peck, and more.

Skull of remains found in a 13th century Dominican monastery on Margaret Island, Budapest, Hungary Credit: Eötvös Loránd University

It’s a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’re experimenting with a monthly collection. November’s list includes forensic details of the medieval assassination of a Hungarian duke, why woodpeckers grunt when they peck, and more evidence that X’s much-maligned community notes might actually help combat the spread of misinformation after all.

An assassinated medieval Hungarian duke

The observed perimortem lesions on the human remains (CL=cranial lesion, PL= Postcranial lesion). The drawing of the skeleton was generated using OpenAI’s image generation tools (DALL·E) via ChatGPT. — Credit: Tamás Hajdu et al., 2026

Back in 1915, archaeologists discovered the skeletal remains of a young man in a Dominican monastery on Margaret Island in Budapest, Hungary. The remains were believed to be those of Duke Bela of Masco, grandson of the medieval Hungarian King Bela IV. Per historical records, the young duke was brutally assassinated in 1272 by a rival faction and his mutilated remains were recovered by the duke’s sister and niece and buried in the monastery.

The identification of the remains was based on a contemporary osteological analysis, but they were subsequently lost and only rediscovered in 2018. A paper published in the journal Forensic Science International: Genetics has now confirmed that identification and shed more light on precisely how the duke died. (A preprint is available on bioRxiv.]

An interdisciplinary team of researchers performed various kinds of bioarchaeological analysis on the remains. including genetic testing, proteomics, 3D modeling, and radiocarbon dating. The resulting data definitively proves that the skeleton is indeed that of Duke Bela of Masco.

The authors were also able to reconstruct the manner of the duke’s death, concluding that this was a coordinated attack by three people. One attacked from the front while the other two attacked from the left and right sides, and the duke was facing his assassins and tried to defend himself. The weapons used were most likely a saber and a long sword, and the assassins kept raining down blows even after the duke had fallen to the ground. The authors concluded that while the attack was clearly planned, it was also personal and fueled by rage or hate.

DOI: Forensic Science International: Genetics, 2025. 10.1016/j.fsigen.2025.103381 (About DOIs).

Why woodpeckers grunt when they peck

A male Pileated woodpecker foraging on a t

Woodpeckers energetically drum away at tree trunks all day long with their beaks and yet somehow never seem to get concussions, despite the fact that such drumming can produce deceleration forces as high as 1,200 g’s. (Humans suffer concussions with a sudden deceleration of just 100 g’s.) While popular myth holds that woodpecker heads are structured in such a way to absorb the shock, and there has been some science to back that up, more recent research found that their heads act more like hammers than shock absorbers. A paper published in the Journal of Experimental Biology sheds further light on the biomechanics of how woodpeckers essentially turn themselves into hammers and reveals that the birds actually grunt as they strike wood.

The authors caught eight wild downy woodpeckers and recorded them drilling and tapping on pieces of hardwood in the lab for three days, while also measuring electrical signals in their heads, necks, abdomens, tails, and leg muscles. Analyzing the footage, they found that woodpeckers use their hip flexors and front neck muscles to propel themselves forward as they peck while tipping their heads back and bracing themselves using muscles at the base of the skull and back of the neck. The birds use abdominal muscles for stability and brace for impact using their tail muscles to anchor their bodies against a tree. As for the grunting, the authors noted that it’s a type of breathing pattern used by tennis players (and martial artists) to boost the power of a strike.

DOI: Journal of Experimental Biology, 2025. 10.1242/jeb.251167 (About DOIs).

Raisins turn water into wine

wine glass half filled with raisins — Credit: Kyoto University

Fermentation has been around in some form for millennia, relying on alcohol-producing yeasts like Saccharomyces cerevisiae; cultured S. cerevisiae is still used by winemakers today. It’s long been thought that winemakers in ancient times stored fresh crushed grapes in jars and relied on natural fermentation to work its magic, but recent studies have called this into question by demonstrating that S. cerevisiae colonies usually don’t form on fresh grape skins. But the yeast does like raisins, as Kyoto University researchers recently discovered. They’ve followed up that earlier work with a paper published in Scientific Reports, demonstrating that it’s possible to use raisins to turn water into wine.

The authors harvested fresh grapes and dried them for 28 days. Some were dried using an incubator, some were sun-dried, and a third batch was dried using a combination of the two methods. The researchers then added the resulting raisins to bottles of water—three samples for each type of drying process—sealed the bottles, and stored them at room temperature for two weeks. One incubator-dried sample and two combo samples successfully fermented, but all three of the sun-dried samples did so, and at higher ethanol concentrations. Future research will focus on identifying the underlying molecular mechanisms. And for those interested in trying this at home, the authors warn that it only works with naturally sun-dried raisins, since store-bought varieties have oil coatings that block fermentation.

DOI: Scientific Reports, 2025. 10.1038/s41598-025-23715-3 (About DOIs).

An octopus-inspired pigment

An octopus camouflages itself with the seafloor. — Credit: Charlotte Seid

Octopuses, cuttlefish, and several other cephalopods can rapidly shift the colors in their skin thanks to that skin’s unique complex structure, including layers of chromatophores, iridophores, and leucophores. A color-shifting natural pigment called xanthommatin also plays a key role, but it’s been difficult to study because it’s hard to harvest enough directly from animals, and lab-based methods of making the pigment are labor-intensive and don’t yield much. Scientists at the University of San Diego have developed a new method for making xanthommatin in substantially larger quantities, according to a paper published in Nature Biotechnology.

The issue is that trying to get microbes to make foreign compounds creates a metabolic burden, and the microbes hence resist the process, hindering yields. The USD team figured out how to trick the cells into producing more xanthommatin by genetically engineering them in such a way that making the pigment was essential to a cell’s survival. They achieved yields of between 1 and 3 grams per liter, compared to just five milligrams of pigment per liter using traditional approaches. While this work is proof of principle, the authors foresee such future applications as photoelectronic devices and thermal coatings, dyes, natural sunscreens, color-changing paints, and environmental sensors. It could also be used to make other kinds of chemicals and help industries shift away from older methods that rely on fossil fuel-based materials.

DOI: Nature Biotechnology, 2025. 10.1038/s41587-025-02867-7 (About DOIs).

A body-swap robot

Participant standing on body-swap balance robot — Credit: Sachi Wickramasinghe/UBC Media Relations

Among the most serious risks facing older adults is falling. According to the authors of a paper published in Science Robotics, standing upright requires the brain to coordinate signals from the eyes, inner ears, and feet to counter gravity, and there’s a natural lag in how fast this information travels back and forth between brain and muscles. Aging and certain diseases like diabetic neuropathy and multiple sclerosis can further delay that vital communication; the authors liken it to steering a car with a wheel that responds half a second late. And it’s a challenge to directly study the brain under such conditions.

That’s why researchers at the University of British Columbia built a large “body swap” robotic platform. Subjects stood on force plates attached to a motor-driven backboard to reproduce the physical forces at play when standing upright: gravity, inertia, and “viscosity,” which in this case describes the damping effect of muscles and joints that allow us to lean without falling. The platform is designed to subtly alter those forces and also add a 200-millisecond delay.

The authors tested 20 participants and found that lowering inertia and making the viscosity negative resulted in similar instability to that which resulted from a signal delay. They then brought in ten new subjects to study whether adjusting body mechanics could compensate for information delays. They found that adding inertia and viscosity could at least partially counter the instability that arose from signal delay—essentially giving the body a small mechanical boost to help the brain maintain balance. The eventual goal is to design wearables that offer gentle resistance when an older person starts to lose their balance, and/or help patients with MS, for example, adjust to slower signal feedback.

DOI: Science Robotics, 2025. 10.1126/scirobotics.adv0496 (About DOIs).

X community notes might actually work

cropped image of phone screen showing an X post with a community note underneath — Credit: Huaxia Rui

Earlier this year, Elon Musk claimed that X’s community notes feature needed tweaking because it was being gamed by “government & legacy media” to contradict Trump—despite vigorously defending the robustness of the feature against such manipulation in the past. A growing body of research seems to back Musk’s earlier stance.

For instance, last year Bloomberg pointed to several studies suggesting that crowdsourcing worked just as well as using professional fact-checkers when assessing the accuracy of news stories. The latest evidence that crowd-sourcing fact checks can be effective at curbing misinformation comes from a paper published in the journal Information Systems Research, which found that X posts with public corrections were 32 percent more likely to be deleted by authors.

Co-author Huaxia Rui of the University of Rochester pointed out that community notes must meet a threshold before they will appear publicly on posts, while those that do not remain hidden from public view. Seeing a prime opportunity in the arrangement, Rui et al. analyzed 264,600 X posts that had received at least one community note and compared those just above and just below that threshold. The posts were collected from two different periods: June through August 2024, right before the US presidential election (when misinformation typically surges), and the post-election period of January and February 2025.

The fact that roughly one-third of authors responded to public community notes by deleting the post suggests that the built-in dynamics of social media (e.g., status, visibility, peer feedback) might actually help improve the spread of misinformation as intended. The authors concluded that crowd-checking “strikes a balance between First Amendment rights and the urgent need to curb misinformation.” Letting AI write the community notes, however, is probably still a bad idea.

DOI: Information Systems Research, 2025. 10.1287/isre.2024.1609 (About DOIs).

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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Many genes associated with dog behavior influence human personalities, too

Behavioral science, Biology, Dogs, Genetics, Genomics, golden retrievers, Science / Kris Guyer / November 26, 2025

Many dog breeds are noted for their personalities and behavioral traits, from the distinctive vocalizations of huskies to the herding of border collies. People have worked to identify the genes associated with many of these behaviors, taking advantage of the fact that dogs can interbreed. But that creates its own experimental challenges, as it can be difficult to separate some behaviors from physical traits distinctive to the breed—small dog breeds may seem more aggressive simply because they feel threatened more often.

To get around that, a team of researchers recently did the largest gene/behavior association study within a single dog breed. Taking advantage of a population of over 1,000 golden retrievers, they found a number of genes associated with behaviors within that breed. A high percentage of these genes turned out to correspond to regions of the human genome that have been associated with behavioral differences as well. But, in many cases, these associations have been with very different behaviors.

Gone to the dogs

The work, done by a team based largely at Cambridge University, utilized the Golden Retriever Lifetime Study, which involved over 3,000 owners of these dogs filling out annual surveys that included information on their dogs’ behavior. Over 1,000 of those owners also had blood samples obtained from their dogs and shipped in; the researchers used these samples to scan the dogs’ genomes for variants. Those were then compared to ratings of the dogs’ behavior on a range of issues, like fear or aggression directed toward strangers or other dogs.

Using the data, the researchers identified when different regions of the genome were frequently associated with specific variants. In total, 14 behavioral tendencies were examined, and 12 genomic regions were associated with specific behaviors, and another nine showed somewhat weaker associations. For many of these traits, it was difficult to find much because golden retrievers are notoriously friendly and mellow dogs, so they tended to score low on traits like aggression and fear.

That result was significant, as some of these same regions of the genome had been associated with very different behaviors in populations that were a mix of breeds. For example, two different regions associated with touch sensitivity in golden retrievers had been linked to a love of chasing and owner-directed aggression in a non-breed-specific study. That finding suggests that the studies were identifying genes that may be involved in setting the stage for behaviors, but were directed into specific outcomes by other genetic or environmental factors.

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AI trained on bacterial genomes produces never-before-seen proteins

AI, bacteria, Biology, Computer science, evolution, Genomics, large language model, Science / Kris Guyer / November 21, 2025

The researchers argue that this setup lets Evo “link nucleotide-level patterns to kilobase-scale genomic context.” In other words, if you prompt it with a large chunk of genomic DNA, Evo can interpret that as an LLM would interpret a query and produce an output that, in a genomic sense, is appropriate for that interpretation.

The researchers reasoned that, given the training on bacterial genomes, they could use a known gene as a prompt, and Evo should produce an output that includes regions that encode proteins with related functions. The key question is whether it would simply output the sequences for proteins we know about already, or whether it would come up with output that’s less predictable.

Novel proteins

To start testing the system, the researchers prompted it with fragments of the genes for known proteins and determined whether Evo could complete them. In one example, if given 30 percent of the sequence of a gene for a known protein, Evo was able to output 85 percent of the rest. When prompted with 80 percent of the sequence, it could return all of the missing sequence. When a single gene was deleted from a functional cluster, Evo could also correctly identify and restore the missing gene.

The large amount of training data also ensured that Evo correctly identified the most important regions of the protein. If it made changes to the sequence, they typically resided in the areas of the protein where variability is tolerated. In other words, its training had enabled the system to incorporate the rules of evolutionary limits on changes in known genes.

So, the researchers decided to test what happened when Evo was asked to output something new. To do so, they used bacterial toxins, which are typically encoded along with an anti-toxin that keeps the cell from killing itself whenever it activates the genes. There are a lot of examples of these out there, and they tend to evolve rapidly as part of an arms race between bacteria and their competitors. So, the team developed a toxin that was only mildly related to known ones, and had no known antitoxin, and fed its sequence to Evo as a prompt. And this time, they filtered out any responses that looked similar to known antitoxin genes.

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The evolution of rationality: How chimps process conflicting evidence

Behavioral science, beliefs, Biology, chimps, evolution, Science / Tim Belzer / November 16, 2025

In the first step, the chimps got the auditory evidence, the same rattling sound coming from the first container. Then, they received indirect visual evidence: a trail of peanuts leading to the second container. At this point, the chimpanzees picked the first container, presumably because they viewed the auditory evidence as stronger. But then the team would remove a rock from the first container. The piece of rock suggested that it was not food that was making the rattling sound. “At this point, a rational agent should conclude, ‘The evidence I followed is now defeated and I should go for the other option,’” Engelmann told Ars. “And that’s exactly what the chimpanzees did.”

The team had 20 chimpanzees participating in all five experiments, and they followed the evidence significantly above chance level—in about 80 percent of the cases. “At the individual level, about 18 out of 20 chimpanzees followed this expected pattern,” Engelmann claims.

He views this study as one of the first steps to learn how rationality evolved and when the first sparks of rational thought appeared in nature. “We’re doing a lot of research to answer exactly this question,” Engelmann says.

The team thinks rationality is not an on/off switch; instead, different animals have different levels of rationality. “The first two experiments demonstrate a rudimentary form of rationality,” Engelmann says. “But experiments four and five are quite difficult and show a more advanced form of reflective rationality I expect only chimps and maybe bonobos to have.”

In his view, though, humans are still at least one level above the chimps. “Many people say reflective rationality is the final stage, but I think you can go even further. What humans have is something I would call social rationality,” Engelmann claims. “We can discuss and comment on each other’s thinking and in that process make each other even more rational.”

Sometimes, at least in humans, social interactions can also increase our irrationality instead. But chimps don’t seem to have this problem. Engelmann’s team is currently running a study focused on whether the choices chimps make are influenced by the choices of their fellow chimps. “The chimps only followed the other chimp’s decision when the other chimp had better evidence,” Engelmann says. “In this sense, chimps seem to be more rational than humans.”

Science, 2025. DOI: 10.1126/science.aeb7565

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Wyoming dinosaur mummies give us a new view of duck-billed species

Biology, dinosaurs, duck-billed dinosaurs, fossils, paleontology, Science / Paul Patrick / November 15, 2025

Exquisitely preserved fossils come from a single site in Wyoming.

The scaly skin of a crest over the back of the juvenile duck-billed dinosaur Edmontosaurus annectens. Credit: Tyler Keillor/Fossil Lab

Edmontosaurus annectens, a large herbivore duck-billed dinosaur that lived toward the end of the Cretaceous period, was discovered back in 1908 in east-central Wyoming by C.H. Sternberg, a fossil collector. The skeleton, later housed at the American Museum of Natural History in New York and nicknamed the “AMNH mummy,” was covered by scaly skin imprinted in the surrounding sediment that gave us the first approximate idea of what the animal looked like.

More than a century later, a team of paleontologists led by Paul C. Sereno, a professor of organismal biology at the University of Chicago, got back to the same exact place where Sternberg dug up the first Edmontosaurus specimen. The researchers found two more Edmontosaurus mummies with all fleshy external anatomy imprinted in a sub-millimeter layer of clay. For the first time, we uncovered an accurate image of what Edmontosaurus really looked like, down to the tiniest details, like the size of its scales and the arrangement of spikes on its tail. And we were in for at least a few surprises.

Evolving images

Our view of Edmontosaurus changed over time, even before Sereno’s study. The initial drawing of Edmontosaurus was made in 1909 by Charles R. Knight, a famous paleoartist, who based his visualization on the first specimen found by Sternberg. “He was accurate in some ways, but he made a mistake in that he drew the crest extending throughout the entire length of the body,” Sereno says. The mummy Knight based his drawing on had no tail, so understandably, the artist used his imagination to fill in the gaps and made the Edmontosaurus look a little bit like a dragon.

An update to Knight’s image came in 1984 due to Jack Horner, one of the most influential American paleontologists, who found a section of Edmontosaurus tail that had spikes instead of a crest. “The specimen was not prepared very accurately, so he thought the spikes were rectangular and didn’t touch each other,” Sereno explains. “In his reconstruction he extended the spikes from the tail all the way to the head—which was wrong,” Sereno says. Over time, we ended up with many different, competing visions of Edmontosaurus. “But I think now we finally nailed down the way it truly looked,” Sereno claims.

To nail it down, Sereno’s team retraced the route to where Sternberg found the first Edmontosaurus mummy. This was not easy, because the team had to rely on Sternberg’s notes, which often referred to towns and villages that were no longer on the map. But based on interviews with Wyoming farmers, Sereno managed to reach the “mummy zone,” an area less than 10 kilometers in diameter, surprisingly abundant in Cretaceous fossils.

“To find dinosaurs, you need to understand geology,” Sereno says. And in the “mummy zone,” geological processes created something really special.

Dinosaur templating

The fossils are found in part of the Lance Formation, a geological formation that originated in the last three or so million years of the Cretaceous period, just before the dinosaurs’ extinction. It extends through North Dakota, South Dakota, Wyoming, Montana, and even to parts of Canada. “The formation is roughly 200 meters thick. But when you approach the mummy zone—surprise! The formation suddenly goes up to a thousand meters thick,” Sereno says. “The sedimentation rate in there was very high for some reason.”

Sereno thinks the most likely reason behind the high sedimentation rate was frequent and regular flooding of the area by a nearby river. These floods often drowned the unfortunate dinosaurs that roamed there and covered their bodies with mud and clay that congealed against a biofilm which formed at the surface of decaying carcasses. “It’s called clay templating, where the clay sticks to the outside of the skin and preserves a very thin layer, a mask, showing how the animal looked like,” Sereno says.

Clay templating is a process well-known by scientists studying deep-sea invertebrate organisms because that’s the only way they can be preserved. “It’s just no one ever thought it could happen to a large dinosaur buried in a river,” Sereno says. But it’s the best explanation for the Wyoming mummy zone, where Sereno’s team managed to retrieve two more Edmontosaurus skeletons surrounded by clay masks under 1 millimeter thick. These revealed the animal’s appearance with amazing, life-like accuracy.

As a result, the Edmontosaurus image got updated one more time. And some of the updates were rather striking.

Delicate elephants

Sereno’s team analyzed the newly discovered Edmontosaurus mummies with a barrage of modern imaging techniques like CT scans, X-rays, photogrammetry, and more. “We created a detailed model of the skin and wrapped it around the skeleton—some of these technologies were not even available 10 years ago,” Sereno says. The result was an updated Edmontosaurus image that includes changes to the crest, the spikes, and the appearance of its skin. Perhaps most surprisingly, it adds hooves to its legs.

It turned out both Knight and Horner were partially right about the look of Edmontosaurus’ back. The fleshy crest, as depicted by Knight, indeed started at the top of the head and extended rearward along the spine. The difference was that there was a point where this crest changed into a row of spikes, as depicted in the Horner version. The spikes were similar to the ones found on modern chameleons, where each spike corresponds one-to-one with the vertebrae underneath it.

“Another thing that was stunning in Edmontosaurus was the small size of its scales,” Sereno says. Most of the scales were just 1 to 4 millimeters across. They grew slightly larger toward the bottom of the tail, but even there they did not exceed 1 centimeter. “You can find such scales on a lizard, and we’re talking about an animal the size of an elephant,” Sereno adds. The skin covered with these super-tiny scales was also incredibly thin, which the team deduced from the wrinkles they found in their imagery.

And then came the hooves. “In a hoof, the nail goes around the toe and wraps, wedge-shaped, around its bottom,” Sereno explains. The Edmontosaurus had singular, central hooves on its fore legs with a “frog,” a triangular, rubbery structure at the underside. “They looked very much like equine hooves, so apparently these were not invented by mammals,” Sereno says. “Dinosaurs had them.” The hind legs that supported most of the animal’s weight, on the other hand, had three wedge-shaped hooves wrapped around three digits and a fleshy heel toward the back—a structure found in modern-day rhinos.

“There are so many amazing ‘firsts’ preserved in these duck-billed mummies,” Sereno says. “The earliest hooves were documented in a land vertebrate, the first confirmed hooved reptile, and the first hooved four-legged animal with different forelimb and hindlimb posture.” But Edmontosaurus, while first in many aspects, was not the last species Sereno’s team found in the mummy zone.

Looking for wild things

“When I was walking through the grass in the mummy zone for the first time, the first hill I found a T. rex in a concretion. Another mummy we found was a Triceratops,” Sereno says. Both these mummies are currently being examined and will be covered in the upcoming papers published by Sereno’s team. And both are unique in their own way.

The T. rex mummy was preserved in a surprisingly life-like pose, which Sereno thinks indicates the predator might have been buried alive. Edmontosaurus mummies, on the other hand, were positioned in a death pose, which meant the animals most likely died up to a week before the mud covered their carcasses. This, in principle, should make the T. rex clay mask even more true-to-life, since there should be no need to account for desiccation and decay when reconstructing the animal’s image.

Sereno, though, seems to be even more excited about the Triceratops mummy. “We already found Triceratops scales were 10 times larger than the largest scales on the Edmontosaurus, and its skin had no wrinkles, so it was significantly thicker. And we’re talking about animals of similar size living in the same area and in the same time,” Sereno says. To him, this could indicate that the physiology of the Triceratops and Edmontosaurus was radically different.

“We are in the age of discovery. There are so many things to come. It’s just the beginning,” Sereno says. “Anyway, the next two mummies we want to cover are the Triceratops and the T. Rex. And I can already tell you what we have with the Triceratops is wild,” he adds.

Science, 2025. DOI: 10.1126/science.adw3536

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.

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World’s oldest RNA extracted from Ice Age woolly mammoth

ancient DNA, ancient RNA, Biology, evolution, Genomics, mammoths, paleontology, Science / Rejus Almole / November 14, 2025

A young woolly mammoth now known as Yuka was frozen in the Siberian permafrost for about 40,000 years before it was discovered by local tusk hunters in 2010. The hunters soon handed it over to scientists, who were excited to see its exquisite level of preservation, with skin, muscle tissue, and even reddish hair intact. Later research showed that, while full cloning was impossible, Yuka’s DNA was in such good condition that some cell nuclei could even begin limited activity when placed inside mouse eggs.

Now, a team has successfully sequenced Yuka’s RNA—a feat many researchers once thought impossible. Researchers at Stockholm University carefully ground up bits of muscle and other tissue from Yuka and nine other woolly mammoths, then used special chemical treatments to pull out any remaining RNA fragments, which are normally thought to be much too fragile to survive even a few hours after an organism has died. Scientists go to great lengths to extract RNA even from fresh samples, and most previous attempts with very old specimens have either failed or been contaminated.

A different view

The team used RNA-handling methods adapted for ancient, fragmented molecules. Their scientific séance allowed them to explore information that had never been accessible before, including which genes were active when Yuka died. In the creature’s final panicked moments, its muscles were tensing and its cells were signaling distress—perhaps unsurprising since Yuka is thought to have died as a result of a cave lion attack.

It’s an exquisite level of detail, and one that scientists can’t get from just analyzing DNA. “With RNA, you can access the actual biology of the cell or tissue happening in real time within the last moments of life of the organism,” said Emilio Mármol, a researcher who led the study. “In simple terms, studying DNA alone can give you lots of information about the whole evolutionary history and ancestry of the organism under study. “Obtaining this fragile and mostly forgotten layer of the cell biology in old tissues/specimens, you can get for the first time a full picture of the whole pipeline of life (from DNA to proteins, with RNA as an intermediate messenger).”

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Tiny chips hitch a ride on immune cells to sites of inflammation

Biology, brain-computer interactions, cells, electronics, Science, sensors / Paul Patrick / November 13, 2025

Tiny chips can be powered by infrared light if they’re near the brain’s surface.

An immune cell chemically linked to a CMOS chip. Credit: Yadav, et al.

Standard brain implants use electrodes that penetrate the gray matter to stimulate and record the activity of neurons. These typically need to be put in place via a surgical procedure. To go around that need, a team of researchers led by Deblina Sarkar, an electrical engineer and MIT assistant professor, developed microscopic electronic devices hybridized with living cells. Those cells can be injected into the circulatory system with a standard syringe and will travel the bloodstream before implanting themselves in target brain areas.

“In the first two years of working on this technology at MIT, we’ve got 35 grant proposals rejected in a row,” Sarkar says. “Comments we got from the reviewers were that our idea was very impactful, but it was impossible.” She acknowledges that the proposal sounded like something you can find in science fiction novels. But after more than six years of research, she and her colleagues have pulled it off.

Nanobot problems

In 2022, when Sarkar and her colleagues gathered initial data and got some promising results with their cell-electronics hybrids, the team proposed the project for the National Institutes of Health Director’s New Innovator Award. For the first time, after 35 rejections, it made it through peer review. “We got the highest impact score ever,” Sarkar says.

The reason for that score was that her technology solved three extremely difficult problems. The first, obviously, was making functional electronic devices smaller than cells that can circulate in our blood.

“Previous explorations, which had not seen a lot of success, relied on putting magnetic particles inside the bloodstream and then guiding them with magnetic fields,” Sarkar explains. “But there is a difference between electronics and particles.” Electronics made using CMOS technology (which we use for making computer processors) can generate electrical power from incoming light in the same way as photovoltaics, as well as perform computations necessary for more intelligent applications like sensing. Particles, on the other hand, can only be used to stimulate cells to an extent.

If they ever reach those cells, of course, which was the second problem. “Controlling the devices with magnetic fields means you need to go into a machine the size of an MRI,” Sarkar says. Once the subject is in the machine, an operator looks at where the devices are and tries to move them to where they need to be using nothing but magnetic fields. Sarkar said that it’s tough to do anything other than move the particles in straight lines, which is a poor match for our very complex vasculature.

The solution her team found was fusing the electronics with monocytes, immune cells that can home in on inflammation in our bodies. The idea was that the monocytes would carry the electronics through the bloodstream using the cells’ chemical homing mechanism. This also solved the third problem: crossing the blood-brain barrier that protects the brain from pathogens and toxins. Electronics alone could not get through it; monocytes could.

The challenge was making all these ideas work.

Clicking together

Sarkar’s team built electronic devices made of biocompatible polymer and metallic layers fabricated on silicon wafers using a standard CMOS process. “We made the devices this small with lithography, the technique used in making transistors for chips in our computers,” Sarkar explains. They were roughly 200 nanometers thick and 10 microns in diameter—that kept them subcellular, since a monocyte cell usually measures between 12 and 18 microns. The devices were activated and powered by infrared light at a wavelength that could penetrate several centimeters into the brain.

Once the devices were manufactured and taken off the wafer, the next thing to figure out was attaching them to monocytes.

To do this, the team covered the surfaces of the electronic devices with dibezocyclooctyne, a very reactive molecule that can easily link to other chemicals, especially nitrogen compounds called azides. Then Sarkar and her colleagues chemically modified monocytes to place azides on their surfaces. This way, the electronics and cells could quickly snap together, almost like Lego blocks (this approach, called click chemistry, got the 2022 Nobel Prize in chemistry).

The resulting solution of cell-electronics hybrids was designed to be biocompatible and could be injected into the circulatory system. This is why Sarkar called her concept “circulatronics.”

Of course, Sarkar’s “circulatronic” hybrids fall a bit short of sci-fi fantasies, in that they aren’t exactly literal nanobots. But they may be the closest thing we’ve created so far.

Artificial neurons

To test these hybrids in live mice, the researchers prepared a fluorescent version to make them easier to track. Mice were anesthetized first, and the team artificially created inflammation at a specific location in their brains, around the ventrolateral thalamic nucleus. Then the hybrids were injected into the veins of the mice. After roughly 72 hours, the time scientists expected would be needed for the monocytes to reach the inflammation, Sarkar and her colleagues started running tests.

It turned out that most of the injected hybrids reached their destination in one piece—the electronics mostly remained attached to the monocytes. The team’s measurements suggest that around 14,000 hybrids managed to successfully implant themselves near the neurons in the target area of the brain. Then, in response to infrared irradiation, they caused significant neuronal activation, comparable to traditional electrodes implanted via surgery.

The real strength of the hybrids, Sarkar thinks, is the way they can be tuned to specific diseases. “We chose monocytes for this experiment because inflammation spots in the brain are usually the target in many neurodegenerative diseases,” Sarkar says. Depending on the application, though, the hybrids’ performance can be adjusted by manipulating their electronic and cellular components. “We have already tested using mesenchymal stem cells for the Alzheimer’s, or T cells and other neural stem cells for tumors,” Sarkar explains.

She went on to say that her technology one day may help with placing the implants in brain regions that today cannot be safely reached through surgery. “There is a brain cancer called glioblastoma that forms diffused tumor sites. Another example is DIPG [a form of glioma], which is a terminal brain cancer in children that develops in a region where surgery is impossible,” she adds.

But in the more distant future, the hybrids can find applications beyond targeting diseases. Most of the studies that have relied on data from brain implants were limited to participants who suffered from severe brain disorders. The implants were put in their brains for therapeutic reasons, and participating in research projects was something they just agreed to do on the side.

Because the electronics in Sarkar’s hybrids can be designed to fully degrade after a set time, the team thinks this could potentially enable them to gather brain implant data from healthy people—the implants would do their job for the duration of the study and be gone once it’s done. Unless we want them to stay, that is.

“The ease of application can make the implants feasible in brain-computer interfaces designed for healthy people,” Sarkar argues. “Also, the electrodes can be made to work as artificial neurons. In principle, we could enhance ourselves—increase our neuronal density.”

First, though, the team wants to put the hybrids through a testing campaign on larger animals and then get them FDA-approved for clinical trials. Through Cahira Technologies, an MIT spinoff company founded to take the “circulatronics” technology to the market, Sarkar wants to make this happen within the next three years.

Nature Biotechnology, 2025. DOI: 10.1038/s41587-025-02809-3

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.

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Some stinkbugs’ legs carry a mobile fungal garden

agriculture, Biology, bugs, entomology, fungus, insects, Science / Rejus Almole / November 4, 2025

Many insect species hear using tympanal organs, membranes roughly resembling our eardrums but located on their legs. Grasshoppers, mantises, and moths all have them, and for decades, we thought that female stinkbugs of the Dinidoridae family have them, too, although located a bit unusually on their hind rather than front legs.

Suspecting that they use their hind leg tympanal organs to listen to male courtship songs, a team of Japanese researchers took a closer look at the organs in Megymenum gracilicorne, a Dinidoridae stinkbug species native to Japan. They discovered that these “tympanal organs” were not what they seemed. They’re actually mobile fungal nurseries of a kind we’ve never seen before.

Portable gardens

Dinidoridae is a small stinkbug family that lives exclusively in Asia. The bug did attract some scientific attention, but not nearly as much as its larger relatives like Pentatomidae. Prior work looking specifically into organs growing on the hind legs of Dinidoridae females was thus somewhat limited. “Most research relied on taxonomic and morphological approaches. Some taxonomists did describe that female Dinidoridae stinkbugs have an enlarged part on the hind legs that looks like the tympanal organ you can find, for example, in crickets,” said Takema Fukatsu, an evolutionary biologist at the National Institute of Advanced Industrial Science and Technology in Tokyo.

Based on that appearance, these parts were classified as tympanal organs—the case was closed, and it stayed closed until Fukatsu’s team started examining them more closely. Most insects have tympanal organs on their front legs, not hind legs, or on abdominal segments. The initial goal of Fukatsu’s study was to figure out what impact this unusual position has on Dinidoridae females’ ability to hear sounds.

Early on in the study, it turned out that whatever Dinidoridae females have on their hind legs, they are not tympanal organs. “We found no tympanal membrane and no sensory neurons, so the enlarged parts on the hind legs had nothing to do with hearing,” Fukatsu explained. Instead, the organ had thousands of small pores filled with benign filamentous fungi. The pores were connected to secretory cells that released substances that Fukatsu’s team hypothesized were nutrients enabling the fungi to grow.

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Neural network finds an enzyme that can break down polyurethane

AI, biochemistry, Biology, chemistry, enzymes, neural networks, polymers, polyurethane, protein design, proteins, Science / Tim Belzer / October 31, 2025

You’ll often hear plastic pollution referred to as a problem. But the reality is that it’s multiple problems. Depending on the properties we need, we form plastics out of different polymers, each of which is held together by a distinct type of chemical bond. So the method we use to break down one type of polymer may be incompatible with the chemistry of another.

That problem is why, even though we’ve had success finding enzymes that break down common plastics like polyesters and PET, they’re only partial solutions to plastic waste. However, researchers aren’t sitting back and basking in the triumph of partial solutions, and they’ve now got very sophisticated protein design tools to help them out.

That’s the story behind a completely new enzyme that researchers developed to break down polyurethane, the polymer commonly used to make foam cushioning, among other things. The new enzyme is compatible with an industrial-style recycling process that breaks the polymer down into its basic building blocks, which can be used to form fresh polyurethane.

Breaking down polyurethane

Image of a set of chemical bonds. From left to right there is an X, then a single bond to an oxygen, then a single bond to an oxygen that's double-bonded to carbon, then a single bond to a nitrogen, then a single bond to another X. — The basics of the chemical bonds that link polyurethanes. The rest of the polymer is represented by X’s here.

The new paper that describes the development of this enzyme lays out the scale of the problem: In 2024, we made 22 million metric tons of polyurethane. The urethane bond that defines these involves a nitrogen bonded to a carbon that in turn is bonded to two oxygens, one of which links into the rest of the polymer. The rest of the polymer, linked by these bonds, can be fairly complex and often contains ringed structures related to benzene.

Digesting polyurethanes is challenging. Individual polymer chains are often extensively cross-linked, and the bulky structures can make it difficult for enzymes to get at the bonds they can digest. A chemical called diethylene glycol can partially break these molecules down, but only at elevated temperatures. And it leaves behind a complicated mess of chemicals that can’t be fed back into any useful reactions. Instead, it’s typically incinerated as hazardous waste.

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Why imperfection could be key to Turing patterns in nature

animals, Biology, Science, Turing mechanism, Turing patterns / Rejus Almole / October 27, 2025

In essence, it’s a type of symmetry breaking. Any two processes that act as activator and inhibitor will produce periodic patterns and can be modeled using Turing’s diffusion function. The challenge is moving from Turing’s admittedly simplified model to pinpointing the precise mechanisms serving in the activator and inhibitor roles.

This is especially challenging in biology. Per the authors of this latest paper, the classical approach to a Turing mechanism balances reaction and diffusion using a single length scale, but biological patterns often incorporate multiscale structures, grain-like textures, or certain inherent imperfections. And the resulting patterns are often much blurrier than those found in nature.

Can you say “diffusiopherosis”?

Simulated hexagon and stripe patterns obtained by diffusiophoretic assembly of two types of cells on top of the chemical patterns. Credit: Siamak Mirfendereski and Ankur Gupta/CU Boulder

In 2023, UCB biochemical engineers Ankur Gupta and Benjamin Alessio developed a new model that added diffusiopherosis into the mix. It’s a process by which colloids are transported via differences in solute concentration gradients—the same process by which soap diffuses out of laundry in water, dragging particles of dirt out of the fabric. Gupta and Alessio successfully used their new model to simulate the distinctive hexagon pattern (alternating purple and black) on the ornate boxfish, native to Australia, achieving much sharper outlines than the model originally proposed by Turing.

The problem was that the simulations produced patterns that were too perfect: hexagons that were all the same size and shape and an identical distance apart. Animal patterns in nature, by contrast, are never perfectly uniform. So Gupta and his UCB co-author on this latest paper, Siamak Mirfendereski, figured out how to tweak the model to get the pattern outputs they desired. All they had to do was define specific sizes for individual cells. For instance, larger cells create thicker outlines, and when they cluster, they produce broader patterns. And sometimes the cells jam up and break up a stripe. Their revised simulations produced patterns and textures very similar to those found in nature.

“Imperfections are everywhere in nature,” said Gupta. “We proposed a simple idea that can explain how cells assemble to create these variations. We are drawing inspiration from the imperfect beauty of [a] natural system and hope to harness these imperfections for new kinds of functionality in the future.” Possible future applications include “smart” camouflage fabrics that can change color to better blend with the surrounding environment, or more effective targeted drug delivery systems.

Matter, 2025. DOI: 10.1016/j.matt.2025.102513 (About DOIs).

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