Biology – Page 2

DNA analysis reveals likely pathogens that killed Napoleon’s army

Biology, DNA analysis, forensic archaeology, history, Napoleon Bonaparte, pathogens, Science / Rejus Almole / October 25, 2025

State-of-the-art methodologies

Rascovan and his co-authors note in their paper that the 2006 study relied upon outdated PCR-based technologies for its DNA analysis. As for the virus family detected in the Kalingrad dental pulp, they argue that those viruses are both ubiquitous and usually asymptomatic in humans—and thus are unlikely to be the primary culprits for the diseases that wiped out the French army. So Rascovan’s team decided to use current state-of-the-art DNA methodologies to re-analyze a different set of remains of Napoleonic soldiers who died in Vilnius.

“In most ancient human remains, pathogen DNA is extremely fragmented and only present in very low quantities, which makes it very difficult to obtain whole genomes,” said Rascovan. “So we need methods capable of unambiguously identifying infectious agents from these weak signals, and sometimes even pinpointing lineages, to explore the pathogenic diversity of the past.”

An 1812 report from one of Napoleon’s physicians, J.R.L. de Kirckhoff, specifically noted typhus, dysentery, and diarrhea after the soldiers arrived in Vilnius, which he attributed to large barrels of salted beets the starving troops consumed, “greatly upsetting us and strongly irritating the intestinal tract.” Rascovan et al. note that such symptoms could accompany any number of conditions or diseases common to 19th-century Europe. “Even today, two centuries later, it would still be impossible to perform a differential diagnosis between typhus, typhoid, or paratyphoid fever based solely on the symptoms or the testimonies of survivors,” the authors wrote.

Imperial Guard button discovered during excavation. Credit: UMR 6578 Aix-Marseille Université, CNRS, EFS

Over 3,200 individual remains, almost all men between the ages of 20 and 50, were excavated from the mass grave at Vilnius. Rascovan et al. focused on 13 teeth from 13 different individuals. To compensate for the degraded nature of the 200-year-old genome fragments, co-authors at the University of Tartu in Estonia helped develop a multistep authentication method to more accurately identify pathogens in the samples. In some cases, they were even able to identify a specific lineage.

DNA analysis reveals likely pathogens that killed Napoleon’s army Read More »

Clinical trial of a technique that could give everyone the best antibodies

antibodies, Biology, DNA, electroporation, medicine, plasmid, Policy, Science / Paul Patrick / October 24, 2025

If we ID the DNA for a great antibody, anyone can now make it.

One of the things that emerging diseases, including the COVID and Zika pandemics, have taught us is that it’s tough to keep up with infectious diseases in the modern world. Things like air travel can allow a virus to spread faster than our ability to develop therapies. But that doesn’t mean biotech has stood still; companies have been developing technologies that could allow us to rapidly respond to future threats.

There are a lot of ideas out there. But this week saw some early clinical trial results of one technique that could be useful for a range of infectious diseases. We’ll go over the results as a way to illustrate the sort of thinking that’s going on, along with the technologies we have available to pursue the resulting ideas.

The best antibodies

Any emerging disease leaves a mass of antibodies in its wake—those made by people in response to infections and vaccines, those made by lab animals we use to study the infectious agent, and so on. Some of these only have a weak affinity for the disease-causing agent, but some of them turn out to be what are called “broadly neutralizing.” These stick with high affinity not only to the original pathogen, but most or all of its variants, and possibly some related viruses.

Once an antibody latches on to a pathogen, broadly neutralizing antibodies inactivate it (as their name implies). This is typically because these antibodies bind to a site that’s necessary for a protein’s function. For example, broadly neutralizing antibodies to HIV bind to the proteins that help this virus enter immune cells.

Unfortunately, not everyone develops broadly neutralizing antibodies, and certainly doesn’t do so in time to prevent infections. And we haven’t figured out a way of designing vaccinations that ensure their generation. So we’re often found ourselves stuck with knowing what antibodies we’d like to see people making while having no way of ensuring that they do.

One of the options we’ve developed is to just mass-produce broadly neutralizing antibodies and inject them into people. This has been approved for use against Ebola and provided an early treatment during the COVID pandemic. This approach has some practical limitations, though. For starters, the antibodies have a finite life span in the bloodstream, so injections may need to be repeated. In addition, making and purifying enough antibodies in bulk isn’t the easiest thing in the world, and they generally need to be kept refrigerated during the distribution, limiting the areas where they can be used.

So, a number of companies have been looking at an alternative: getting people to make their own. This could potentially lead to longer-lived protection, even ensuring the antibodies are present to block future infections if the DNA survives long enough.

Genes and volts

Once you identify cells that produce broadly neutralizing antibodies, it’s relatively simple to clone those genes and put them into a chunk of DNA that will ensure that they’ll be produced by any human cell. If we could get that DNA into a person’s cells, broadly neutralizing antibodies are the result. And a number of approaches have been tried to handle that “if.” Most of them have inserted the genes needed to make the antibodies into a harmless, non-infectious virus, and then injected that virus into volunteers. Unfortunately, these viruses have tended to set off a separate immune response, which causes more significant side effects and may limit how often this approach can be used.

This brings us to the technique being used here. In this case, the researchers placed the antibody genes in a circular loop of DNA called a plasmid. This is enough to ensure that the DNA doesn’t get digested immediately and to get the antibody genes made into proteins. But it does nothing to help get the DNA inside of cells.

The research team, a mixture of people from a biotech company and academic labs, used a commercial injection setup that mixes the injection of the DNA with short pulses of electricity. The electricity disrupts the cell membrane, allowing the plasmid DNA to make it inside cells. Based on animal testing, doing this in muscle cells is enough to turn the muscles into factories producing lots of broadly neutralizing antibodies.

The new study was meant to test the safety of doing that in humans. The team recruited 44 participants, testing various doses of two antibody-producing plasmids and injection schedules. All but four of the subjects completed the study; three of those who dropped out had all been testing a routine with the electric pulses happening very quickly, which turned out to be unpleasant. Fortunately, it didn’t seem to make any difference to the production of antibodies.

While there were a lot of adverse reactions, most of these were associated with the injection itself: muscle pain at the site, a scab forming afterward, and a reddening of the skin. The worst problem appeared to be a single case of moderate muscle pain that persisted for a couple of days.

In all but one volunteer, the injection resulted in stable production of the two antibodies for at least 72 weeks following the injection; the single exception only made one of the two. That’s “at least” 72 weeks because that’s when they stopped testing—there was no indication that levels were dropping at this point. Injecting more DNA led to more variability in the amount of antibody produced, but that amount quickly maxed out. More total injections also boosted the level of antibody production. But even the minimal procedure—two injections of the lowest concentration tested—resulted in significant and stable antibodies.

And, as expected, these antibodies blocked the virus they were directed against: SARS-CoV-2.

The caveats

This approach seems to work—we can seemingly get anybody to make broadly neutralizing antibodies for months at a time. What’s the hitch? For starters, this isn’t necessarily great for a rapidly emerging pandemic. It takes a while to identify broadly neutralizing antibodies after a pathogen is identified. And, while it’s simple to ship DNA around the world to where it will be needed, injection setups that also produce the small electric pulses are not exactly standard equipment even in industrialized countries, much less the Global South.

Then there’s the issue of whether this really is a longer-term fix. Widespread use of broadly neutralizing antibodies will create a strong selective pressure for the evolution of variants that the antibody can no longer bind to. That may not always be a problem—broadly neutralizing antibodies generally bind to parts of proteins that are absolutely essential for the proteins’ function, and so it may not be possible to change those while maintaining the function. But that’s unlikely to always be the case.

In the end, however, social acceptance may end up being the biggest problem. People had an utter freakout over unfounded conspiracies that the RNA of COVID vaccines would somehow lead to permanent genetic changes. Presumably, having DNA that’s stable for months would be even harder for some segments of the public to swallow.

Nature Medicine, 2025. DOI: 10.1038/s41591-025-03969-0 (About DOIs).

John is Ars Technica’s science editor. He has a Bachelor of Arts in Biochemistry from Columbia University, and a Ph.D. in Molecular and Cell Biology from the University of California, Berkeley. When physically separated from his keyboard, he tends to seek out a bicycle, or a scenic location for communing with his hiking boots.

Clinical trial of a technique that could give everyone the best antibodies Read More »

Bats eat the birds they pluck from the sky while on the wing

bats, Biology, birds, Ecology, hunting, Science / Kris Guyer / October 24, 2025

There are three species of bats that eat birds. We know that because we have found feathers and other avian remains in their feces. What we didn’t know was how exactly they hunt birds, which are quite a bit heavier, faster, and stronger than the insects bats usually dine on.

To find out, Elena Tena, a biologist at Doñana Biological Station in Seville, Spain, and her colleagues attached ultra-light sensors to Nyctalus Iasiopterus, the largest bats in Europe. What they found was jaw-droppingly brutal.

Inconspicuous interceptors

Nyctalus Iasiopterus, otherwise known as greater noctule bats, have a wingspan of about 45 centimeters. They have reddish-brown or chestnut fur with a slightly paler underside, and usually weigh around 40 to 60 grams. Despite that minimal weight, they are the largest of the three bat species known to eat birds, so the key challenge in getting a glimpse into the way they hunt was finding sensors light enough to not impede the bats’ flight.

Cameras, which are the usual go-to sensor, were out of the question. “Bats hunt at night, so you’d need night vision cameras, which together with batteries are too heavy for a bat to carry. Our sensors had to weigh below 10 percent of the weight of the bat—four to six grams,” Tena explained.

Tena and her team explored several alternative approaches throughout the last decade, including watching the bats from the ground or using military-grade radars. But even then, catching the hunting bats red-handed remained impossible.

In recent years, the technology and miniaturization finally caught up with Tena’s needs, and the team found the right sensors for the job and attached them to 14 greater noctule bats over the course of two years. The tags used in the study weighed around four grams, could run for several hours, and registered sound, altitude, and acceleration. This gave Tena and her colleagues a detailed picture of the bats’ behavior in the night sky. The recordings included both ambient environmental sounds and the ultra-frequency bursts bats use for echolocation. Combining altitude with accelerometer readouts enabled scientists to trace the bats’ movements through all their fast-paced turns, dives, and maneuvers.

Bats eat the birds they pluck from the sky while on the wing Read More »

Dinosaurs may have flourished right up to when the asteroid hit

asteroid, Biology, dinosaurs, evolution, Impact, paleontology, Science / Kris Guyer / October 23, 2025

That seemingly changes as of now, with new argon dating of strata from the Naashoibito Member in the San Juan Basin of present-day New Mexico. Many dinosaur fossils have been obtained from this region, and we know the site differs from the sort of ecosystem found at Hell Creek. But it was previously thought to date back closer to a million years before the mass extinction. The new dates, plus the alignment of magnetic field reversals, tell us that the ecosystem was a contemporary of the one in Hell Creek, and dates to the last few hundred thousand years prior to the mass extinction.

Diverse ecosystems

The fossils at Naashoibito have revealed an ecosystem we now label the “Alamo Wash local fauna.” And they’re fairly distinct from the ones found in Wyoming, despite being just 1,500 kilometers further south. Analyzing the species present using ecological measures, the researchers found that dinosaurs formed two “bioprovinces” in the late Cretaceous—essentially, there were distinct ecosystems present in the northern and southern areas.

This doesn’t seem to be an artifact of the sites, as mammalian fossils seem to reflect a single community across both areas near the mass extinction, but had distinct ecologies both earlier and after. The researchers propose that temperature differences were the key drivers of the distinction, something that may have had less of an impact on mammals, which are generally better at controlling their own temperatures.

Overall, the researchers conclude that, rather than being dominated by a small number of major species, “dinosaurs were thriving in New Mexico until the end of the Cretaceous.”

While this speaks directly to the idea that limited diversity may have primed the dinosaurs for extinction, it also may have implications for the impact of the contemporaneous eruptions in the Deccan Traps. If these were having a major global impact, then it’s a bit unlikely that dinosaurs would be thriving anywhere.

Even with the new data, however, our picture is still limited to the ecosystems present on the North American continent. We do have fossils from elsewhere, but they’re not exactly dated. There are some indications of dinosaurs in the late Cretaceous in Europe and South America, but we don’t have a clear picture of the ecosystems in which they were found. So, while these findings help clarify the diversity of dinosaurs in the time leading up to their extinction, there’s still a lot left to learn.

Science, 2025. DOI: 10.1126/science.adw3282 (About DOIs).

Dinosaurs may have flourished right up to when the asteroid hit Read More »

Termite farmers fine-tune their weed control

agriculture, Biology, entomology, Science, termites / Mike M. / October 10, 2025

Odontotermes obesus is one of the termite species that grows fungi, called Termitomyces, in their mounds. Workers collect dead leaves, wood, and grass to stack them in underground fungus gardens called combs. There, the fungi break down the tough plant fibers, making them accessible for the termites in an elaborate form of symbiotic agriculture.

Like any other agriculturalist, however, the termites face a challenge: weeds. “There have been numerous studies suggesting the termites must have some kind of fixed response—that they always do the same exact thing when they detect weed infestation,” says Rhitoban Raychoudhury, a professor of biological sciences at the Indian Institute of Science Education, “but that was not the case.” In a new Science study, Raychoudhury’s team discovered that termites have pretty advanced, surprisingly human-like gardening practices.

Going blind

Termites do not look like particularly good gardeners at first glance. They are effectively blind, which is not that surprising considering they spend most of their life in complete darkness working in endless corridors of their mounds. But termites make up for their lack of sight with other senses. “They can detect the environment based on advanced olfactory reception and touch, and I think this is what they use to identify the weeds in their gardens,” Raychoudhury says. To learn how termites react once they detect a weed infestation, his team collected some Odontotermes obesus and challenged them with different gardening problems.

The experimental setup was quite simple. The team placed some autoclaved soil sourced from termite mounds into glass Petri dishes. On this soil, Raychoudhury and his colleagues placed two fungus combs in each dish. The first piece acted as a control and was a fresh, uninfected comb with Termitomyces. “Besides acting as a control, it was also there to make sure the termites have the food because it is very hard for them to survive outside their mounds,” Raychoudhury explains. The second piece was intentionally contaminated with Pseudoxylaria, a filamentous fungal weed that often takes over Termitomyces habitats in termite colonies.

Termite farmers fine-tune their weed control Read More »

The neurons that let us see what isn’t there

Biology, Neuroscience, optical illusions, Science, visual system / Kris Guyer / October 6, 2025

Earlier work had hinted at such cells, but Shin and colleagues show systematically that they’re not rare oddballs—they’re a well-defined, functionally important subpopulation. “What we didn’t know is that these neurons drive local pattern completion within primary visual cortex,” says Shin. “We showed that those cells are causally involved in this pattern completion process that we speculate is likely involved in the perceptual process of illusory contours,” adds Adesnik.

Behavioral tests still to come

That doesn’t mean the mice “saw” the illusory contours when the neurons were artificially activated. “We didn’t actually measure behavior in this study,” says Adesnik. “It was about the neural representation.” All we can say at this point is that the IC-encoders could induce neural activity patterns that matched what imaging shows during normal perception of illusory contours.

“It’s possible that the mice weren’t seeing them,” admits Shin, “because the technique has involved a relatively small number of neurons, for technical limitations. But in the future, one could expand the number of neurons and also introduce behavioral tests.”

That’s the next frontier, Adesnik says: “What we would do is photo-stimulate these neurons and see if we can generate an animal’s behavioral response even without any stimulus on the screen.” Right now, optogenetics can only drive a small number of neurons, and IC-encoders are relatively rare and scattered. “For now, we have only stimulated a small number of these detectors, mainly because of technical limitations. IC-encoders are a rare population, probably distributed through the layers [of the visual system], but we could imagine an experiment where we recruit three, four, five, maybe even 10 times as many neurons,” he says. “In this case, I think we might be able to start getting behavioral responses. We’d definitely very much like to do this test.”

Nature Neuroscience, 2025. DOI: 10.1038/s41593-025-02055-5

Federica Sgorbissa is a science journalist; she writes about neuroscience and cognitive science for Italian and international outlets.

The neurons that let us see what isn’t there Read More »

World-famous primatologist Jane Goodall dead at 91

anthropology, Biology, jane goodall, Obituaries, primatology, Science / Mike M. / October 2, 2025

A sculpture of Jane Goodall and David Greybeard outside the Field Museum of Natural History in Chicago Credit: Geary/CC0

David Greybeard’s behavior also challenged the long-held assumption that chimpanzees were vegetarians. Goodall found that chimps would hunt and eat smaller primates like colobus monkeys as well, sometimes sharing the carcass with other troop members. She also recorded evidence of strong bonds between mothers and infants, altruism, compassion, and aggression and violence. For instance, dominant females would sometimes kill the infants of rival females, and from 1974 to 1978, there was a violent conflict between two communities of chimpanzees that became known as the Gombe Chimpanzee War.

Almost human

One of the more colorful chimps Goodall studied was named Frodo, who grew up to be an alpha male with a temperament very unlike his literary namesake. “As an infant, Frodo proved mischievous, disrupting Jane Goodall’s efforts to record data on mother-infant relationships by grabbing at her notebooks and binoculars,” anthropologist Michael Wilson of the University of Minnesota in Saint Paul recalled on his blog when Frodo died from renal failure in 2013. “As he grew older, Frodo developed a habit of throwing rocks, charging at, hitting, and knocking over human researchers and tourists.” Frodo attacked Wilson twice on Wilson’s first trip to Gombe, even beating Goodall herself in 1989, although he eventually lost his alpha status and “mellowed considerably” in his later years, per Wilson.

Goodall became so renowned around the world that she even featured in one of Gary Larson’s Far Side cartoons, in which two chimps are shown grooming when one finds a blonde hair on the other. “Conducting a little more ‘research’ with that Jane Goodall tramp?” the caption read. The JGI was not amused, sending Larson a letter (without Goodall’s knowledge) calling the cartoon an “atrocity,” but their objections were not shared by Goodall herself, who thought the cartoon was very funny when she heard of it. Goodall even wrote a preface to The Far Side Gallery 5. Larson, for his part, visited Goodall’s research facility in Tanzania in 1988, where he experienced Frodo’s alpha aggressiveness firsthand.

A young Jane Goodall in the field. Credit: YouTube/Jane Goodall Institute

Goodall founded the JGI in 1977 and authored more than 27 books, most notably My Friends, the Wild Chimpanzees (1967), In the Shadow of Man (1971), and Through a Window (1990). There was some initial controversy around her 2014 book Seeds of Hope, co-written with Gail Hudson, when portions were found to have been plagiarized from online sources; the publisher postponed publication so that Goodall could revise the book and add 57 pages of endnotes. (She blamed her “chaotic note-taking” for the issue.) National Geographic released a full-length documentary last year about her life’s work, drawing from over 100 hours of previously unseen archival footage.

World-famous primatologist Jane Goodall dead at 91 Read More »

150 million-year-old pterosaur cold case has finally been solved

Biology, fossils, paleontology, pterosaurs, Science / Mike M. / September 28, 2025

Smyth thinks that so few adults show up on the fossil record in this region not only because they were more likely to survive, but also because those that couldn’t were not buried as quickly. Carcasses would float on the water anywhere from days to weeks. As they decomposed, parts would fall to the lagoon bottom. Juveniles were small enough to be swept under and buried quickly by sediments that would preserve them.

Cause of death

The humerus fractures found in Lucky I and Lucky II were especially significant because forelimb injuries are the most common among existing flying vertebrates. The humerus attaches the wing to the body and bears most flight stress, which makes it more prone to trauma. Most humerus fractures happen in flight as opposed to being the result of a sudden impact with a tree or cliff. And these fractures were the only skeletal trauma seen in any of the juvenile pterosaur specimens from Solnhofen.

Evidence suggesting the injuries to the two fledgling pterosaurs happened before death includes the displacement of bones while they were still in flight (something recognizable from storm deaths of extant birds and bats) and the smooth edges of the break, which happens in life, as opposed to the jagged edges of postmortem breaks. There were also no visible signs of healing.

Storms disproportionately affected flying creatures at Solnhofen, which were often taken down by intense winds. Many of Solnhofen’s fossilized vertebrates were pterosaurs and other winged species such as bird ancestor Arachaeopteryx. Flying invertebrates were also doomed.

Even marine invertebrates and fish were threatened by storm conditions, which churned the lagoons and brought deep waters with higher salt levels and low oxygen to the surface. Anything that sank to the bottom was exceptionally preserved because of these same conditions, which were too harsh for scavengers and paused decomposition. Mud kicked up by the storms also helped with the fossilization process by quickly covering these organisms and providing further protection from the elements.

“The same storm events responsible for the burial of these individuals also transported the pterosaurs into the lagoonal basins and were likely the primary cause of their injury and death,” Smyth concluded.

Although Lucky I and Lucky II were decidedly unlucky, the exquisite preservation of their skeletons that shows how they died has finally allowed researchers to solve a case that went cold for over a hundred thousand years.

Current Biology, 2025. DOI: 10.1016/j.cub.2025.08.006

150 million-year-old pterosaur cold case has finally been solved Read More »

$scientists-want-to-treat-complex-bone-fractures-with-a-bone-healing-gun$

Scientists want to treat complex bone fractures with a bone-healing gun

3D printing, Biology, bone, fractures, medicine, Science / Rejus Almole / September 26, 2025

After examining a few candidate formulations, the team found the right material. “We used a biocompatible thermoplastic called polycaprolactone and hydroxyapatite as base materials,” Lee said. Polycaprolactone was chosen because it is an FDA-approved material that degrades in the body within a few months after implantation. The hydroxyapatite, on the other hand, supports bone-tissue regeneration. Lee’s team experimented with various proportions of these two ingredients and finally nailed the formulation that checked all the boxes: It extruded at a relatively harmless 60° Celsius, the mix was mechanically sound, it adhered to the bone well, and it degraded over time.

Once the bone-healing bullets were ready, the team tested them on rabbits. Rabbits with broken femurs treated with Lee’s healing gun recovered faster than those treated with bone cement, which is the closest commercially available alternative. But there is still a lot to do before the healing gun can be tested on humans.

Skill issues

While the experiment on rabbits revealed new bone tissues forming around the implants created with the healing gun, their slow degradation of the implanted material prevented the full restoration of bone tissues. Another improvement Lee plans involves adding antibiotics to the formulation. The implant, he said, will release the drugs over time to prevent infections.

Then there’s the issue of load bearing. Rabbits are fine as test subjects, but they are rather light. “To evaluate the potential to use this technology on humans, we need to look into its long-term safety in large animal models,” Lee said.

Beyond the questions about the material, the level of skill required to operate this healing gun seems rather high.

Extrusion-based 3D printers, the ones that work more or less like very advanced hot glue guns, usually use guiding rods or rails for precise printing head positioning. If those rods or rails are warped, even slightly, the accuracy of your prints will most likely suffer. Achieving comparable precision with a handheld device might be a bit difficult, even for a skilled surgeon. “It is true that the system requires practice,” Lee said. “We may need to integrate it with a guiding mechanism that would position the head of the device precisely. This could be our next-gen bone printing device.”

Device, 2025. DOI: 10.1016/j.device.2025.100873

Scientists want to treat complex bone fractures with a bone-healing gun Read More »

Fiji’s ants might be the canary in the coal mine for the insect apocalypse

ants, Biology, evolution, Fiji, insects, Science, speciation / Tim Belzer / September 26, 2025

A new genetic technique lets museum samples track population dynamics.

In late 2017, a study by Krefeld Entomological Society looked at protected areas across Germany and discovered that two-thirds of the insect populations living in there had vanished over the last 25 years. The results spurred the media to declare we’re living through an “insect apocalypse,” but the reasons behind their absence were unclear. Now, a joint team of Japanese and Australian scientists have completed a new, multi-year study designed to get us some answers.

Insect microcosm

“In our work, we focused on ants because we have systematic ways for collecting them,” says Alexander Mikheyev, an evolutionary biologist at the Australian National University. “They are also a group with the right level of diversity, where you have enough species to do comparative studies.” Choosing the right location, he explained, was just as important. “We did it in Fiji, because Fiji had the right balance between isolation—which gave us a discrete group of animals to study—but at the same time was diverse enough to make comparisons,” Mikheyev adds.

Thus, the Fijian archipelago, with its 330 islands, became the model the team used to get some insights into insect population dynamics. A key difference from the earlier study was that Mikheyev and his colleagues could look at those populations across thousands of years, not just the last 25.

“Most of the previous studies looked at actual observational data—things we could come in and measure,” Mikheyev explains. The issue with those studies was that they could only account for the last hundred years or so, because that’s how long we have been systematically collecting insect samples. “We really wanted to understand what happened in the longer time frame,” Mikheyev says.

To do this, his team focused on community genomics—studying the collective genetic material of entire groups of organisms. The challenge is that this would normally require collecting thousands of ants belonging to hundreds of species across the entire Fijian archipelago. Given that only a little over 100 out of 330 islands in Fiji are permanently inhabited, this seemed like an insurmountable challenge.

To go around it, the team figured they could run its tests on ants already collected in Fijian museums. But that came with its own set of difficulties.

DNA pieces

Unfortunately, the quality of DNA that could be obtained from museum collections was really bad. From the perspective of DNA preservation, the ants were obtained and stored in horrific conditions, since the idea was to showcase them for visitors, not run genetic studies. “People were catching them in malaise traps,” Mikheyev says. “A malaise trap is basically a bottle of alcohol that sits somewhere in Fiji for a month. Those samples had horribly fragmented, degraded DNA.”

To work with this degraded genetic material, the team employed a technique they called high-throughput museumomics, a relatively new technique that looks at genetic differences across a genome without sequencing the whole thing. DNA sampled from multiple individuals was cut and marked with unique tags at the same repeated locations, a bit like using bookmarks to pinpoint the same page or passage in different issues of the same book. Then, the team sequenced short DNA fragments following the tag to look for differences between them, allowing them to evaluate the genetic diversity within a population. “We developed a series of methods that actually allowed us to harness these museum-grade specimens for population genetics,” Mikheyev explains.

But the trouble didn’t end there. Differences among Fijian ant taxa are based on their appearance, not genetic analysis. For years, researchers were collecting various ants and determining their species by looking at them. This led to 144 species belonging to 40 genera. For Mikheyev’s team, the first step was to look at the genomes in the samples and see if these species divisions were right. It turned out that they were mostly correct, but some species had to be split, while others were lumped together. At the end, the team confirmed that 127 species were represented among their samples.

Overall, the team analyzed more than 4,000 specimens of ants collected over the past decade or so. And gradually, a turbulent history of Fijian ants started to emerge from the data.

The first colonists

The art of reconstructing the history of entire populations from individual genetic sequences relies on comparing them to each other thoroughly and running a whole lot of computer simulations. “We had multiple individuals per population,” Mikheyev explains. “Let’s say we look at this population and find it has essentially no diversity. It suggests that it very recently descended from a small number of individuals.” When the contrary was true and the diversity was high, the team assumed it indicated the population had been stable for a long time.

With the DNA data in hand, the team simulated how populations of ants would evolve over thousands of years under various conditions, and picked scenarios that best matched the genetic diversity results it obtained from real ants. “We identified multiple instances of colonization—broadscale evolutionary events that gave rise to the Fijian fauna that happened in different timeframes,” Mikheyev says. There was a total of at least 65 colonization events.

The first ants, according to Mikheyev, arrived at Fiji millions of years ago and gave rise to 88 endemic Fijian ant species we have today. These ants most likely evolved from a single ancestor and then diverged from their mainland relatives. Then, a further 23 colonization events introduced ants that were native to a broader Pacific region. These ants, the team found, were a mixture of species that colonized Fiji naturally and ones that were brought by the first human settlers, the Lapita people, who arrived around 3,000 years ago.

The arrival of humans also matched the first declines in endemic Fijian ant species.

Slash and burn

“In retrospect, these declines are not really surprising,” Mikheyev says. The first Fijian human colonists didn’t have the same population density as we have now, but they did practice things like slash-and-burn agriculture, where forests were cut down, left to dry, and burned to make space for farms and fertilize the soil. “And you know, not every ant likes to live in a field, especially the ones that evolved to live in a forest,” Mikheyev adds. But the declines in Fijian endemic ant species really accelerated after the first contact with the Europeans.

The first explorers in the 17th and 18th centuries, like Abel Tasman and James Cook, charted some of the Fijian islands but did not land there. The real apocalypse for Fijian ants began in the 19th century, when European sandalwood traders started visiting the archipelago on a regular basis and ultimately connected it to the global trade networks.

Besides the firearms they often traded for sandalwood with local chiefs, the traders also brought fire ants. “Fire ants are native to Latin America, and it’s a common invasive species extremely well adapted to habitats we create: lawns or clear-cut fields,” Mikheyev says. Over the past couple of centuries, his team saw a massive increase in fire ant populations, combined with accelerating declines in 79 percent of endemic Fijian ant species.

Signs of apocalypse

To Mikheyev, Fiji was just a proving ground to test the methods of working with museum-grade samples. “Now we know this approach works and we can start leveraging collections found in museums around the world—all of them can tell us stories about places where they were collected,” Mikheyev says. His ultimate goal is to look for the signs of the insect apocalypse, or any other apocalypse of a similar kind, worldwide.

But the question is whether what’s happening is really that bad? After all, not all ants seem to be in decline. Perhaps what we see is just a case of a better-adapted species taking over—natural selection happening before our eyes?

“Sure, we can just live with fire ants all along without worrying about the kind of beautiful biodiversity that evolution has created on Fiji,” Mikheyev says. “But I feel like if we just go with that philosophy, we’re really going to be irreparably losing important and interesting parts of our ecology.” If the current trends persist, he argues, we might lose endemic Fijian ants forever. “And this would make our world worse, in many ways,” Mikheyev says.

Science, 2025. DOI: 10.1126/science.ads3004

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

Fiji’s ants might be the canary in the coal mine for the insect apocalypse Read More »

Scientists catch a shark threesome on camera

animal behavior, aquatic animals, Biology, marine biology, mating, Science, sharks / Rejus Almole / September 23, 2025

Three sharks, two cameras

Three leopard sharks mating - near surface — Moving the action closer to the surface. Credit: Hugo Lassauce/UniSC-Aquarium des Lagons

Lassauce had two GoPro Hero 5 cameras ready at hand, albeit with questionable battery life. That’s why the video footage has two interruptions to the action: once when he had to switch cameras after getting a “low battery” signal, and a second time when he voluntarily stopped filming to conserve the second camera’s battery. Not much happened for 55 minutes, after all, and he wanted to be sure to capture the pivotal moments in the sequence. Lassauce succeeded and was rewarded with triumphant cheers from his fellow marine biologists on the boat, who knew full well the rarity of what had just been documented for posterity.

The lengthy pre-copulation stage involved all three sharks motionless on the seafloor for nearly an hour, after which the female started swimming with one male shark biting onto each of her pectoral fins. A few minutes later, the first male made his move, “penetrating the female’s cloaca with his left clasper.” Claspers are modified pelvic fins capable of transferring sperm. After the first male shark finished, he lay motionless while the second male held onto the female’s other fin. Then the other shark moved in, did his business, went motionless, and the female shark swam away. The males also swam away soon afterward.

Apart from the scientific first, documenting the sequence is a good indicator that this particular area is a critical mating habitat for leopard sharks, and could lead to better conservation strategies, as well as artificial insemination efforts to “rewild” leopard sharks in Australia and several other countries. “It’s surprising and fascinating that two males were involved sequentially on this occasion,” said co-author Christine Dudgeon, also of UniSC, adding, “From a genetic diversity perspective, we want to find out how many fathers contribute to the batches of eggs laid each year by females.”

Journal of Ethology, 2025. DOI: 10.1007/s10164-025-00866-4 (About DOIs).

Scientists catch a shark threesome on camera Read More »

Chimps consume alcohol equivalent of nearly 2 drinks a day

animal behavior, Biology, Science / Tim Belzer / September 20, 2025

Nearly two drinks a day

This latest study involved chimp populations at the Ngogo Chimpanzee Project (Uganda) and a second site at Tai (Ivory Coast), where scientists have estimated the animals consume between 5 to 10 percent of their body weight (about 40 kilos) in fruit each day—around 45 kilograms. The authors collected fallen fruit pulp samples from both sites, packed them in airtight containers, and froze them back at base camp to keep the fruit from ripening further.

Then they quantified the ethanol concentrations using a breathalyzer, a portable gas chromatograph, and chemical testing. The Uganda fruit contained 0.32 percent ethanol, while the Ivory Coast fruit contained 0.31 percent ethanol, which might not sound like much until you consider just how much fruit they eat. And the most frequently consumed fruit at both sites had the highest ethanol content.

If anything, this is a conservative estimate, per Dudley. “If the chimps are randomly sampling ripe fruit, then that’s going to be their average consumption rate, independent of any preference for ethanol,” he said. “But if they are preferring riper and/or more sugar-rich fruits, then this is a conservative lower limit for the likely rate of ethanol ingestion.” That’s in keeping with a 2016 report that captive aye-ayes and slow lorises prefer nectar with the highest alcohol content.

“Our findings imply that our ancestors were similarly chronically exposed to dietary alcohol,” co-author Aleksey Maro, a graduate student at UC Berkeley, told New Scientist. “The drunken monkey hypothesis suggests that this exposure caused our species to evolve an association between alcohol consumption and the reward of finding fruit sugars, and explains human attraction to alcohol today.” One caveat is that apes ingest ethanol accidentally, while humans drink it deliberately.

“What we’re realizing from this work is that our relationship with alcohol goes deep back into evolutionary time, probably about 30 million years,” University of St. Andrews primatologist Catherine Hobaiter, who was not involved with the study, told BBC News. “Maybe for chimpanzees, this is a great way to create social bonds, to hang out together on the forest floor, eating those fallen fruits.”

The next step is to sample the chimps’ urine to see if it contains any alcohol metabolites, as was found in a 2022 study on spider monkeys. This will further refine estimates for how much ethanol-laden fruit the chimps eat every day. Maro spent this summer in Ngogo, sleeping in trees—protected from the constant streams by an umbrella—to collect urine samples.

Science Advances, 2025. DOI: 10.1126/sciadv.adw1665 (About DOIs).

Chimps consume alcohol equivalent of nearly 2 drinks a day Read More »