Scientists Recovered 22,000-Year-Old Human DNA From Cave Dirt

01 Nov. 2026,m By C. Cassella

https://www.sciencealert.com/scientists-recovered-22000-year-old-human-dna-from-cave-dirt

(Jordi Salas/Moment RF/Getty Images)

Scientists are getting astonishingly good at extracting ancient human DNA from mere dirt and dust, even when there are no physical remains left…

No bones, no teeth, no fossils.

A small scoop of sediment from a cave in Spain has now offered up ancient DNA from several individuals who lived roughly 22,000 years ago.

No human remains exist in this layer of the El Mirón Cave, but that hasn't stopped scientists.

The sediment taken from the El Mirón Cave weighed no more than a few grains of rice and had to be sequenced 100 times to yield enough usable data.

The team had to sift through more than a billion DNA fragments in the sample to find any human traces.

Plus, modern contamination had to be accounted for as well.

The findings from the study, led by researchers at the University of Vienna in Austria, are published in Science Advances.

What little genetic information the team found was probably shed long, long ago, possibly from the skin, hair, or blood of ancient humans sheltering in the cave during the coldest time of Europe's last ice age.

Skeletons from this period are extremely rare.

In fact, there are only a few human remains that have been found from this time and culture, and two are of very poor quality.

This new research at El Mirón adds crucial genetic information to the picture.

This ancient human DNA suggests that the people who once inhabited this cave probably belonged to a western ancestry group with dark skin, hair, and eyes.

The DNA seems to have come from a mix of individuals, including more males than females.

"This result highlights the capacity of sedaDNA (sedimentary DNA) for uncovering previously inaccessible genetic dynamics in absence of human remains," the authors conclude, "and decisively connects archeological records with human genetic identities."

El Mirón Cave. 

(Gabinete de Prensa del Gobierno de Cantabria/CC BY 3.0)



As you can imagine, SedaDNA is on track to revolutionize the field of archaeology.

Without the need for physical human remains, experts may no longer be limited by a fossil record in the same way.

The challenges of this technology still need to be ironed out, but with work, a 2025 review argues that sedaDNA could lead to a much deeper understanding of human dispersal dynamics, hunter-gatherer interactions, early agriculture, domestication, and disease.

"This takes archaeology to a whole new level of processual research in some of the most exciting areas of modern archaeology, including mobility, diet, and family stories," the review argued.

"The application of sedaDNA to a wide variety of archaeological sites and questions will increase rapidly in the next few years," the authors predicted.

Already, the results are starting to roll in.

In 2021, for instance, researchers pulled mitochondrial DNA from the mud floor of a cave in Georgia.

The genetic information once belonged to a woman who lived 25,000 years ago.

Just this year, another sample of ancient human DNA was found preserved on the wall of a cave in Argentina decorated with rock art.

"Although we cannot directly connect the traces of ancient human DNA we have found to the creation of rock art," explained Alba Bossoms Mesa, an evolutionary anthropologist at the Max Planck Institute.

"This is the first evidence for human DNA preservation on cave walls for thousands of years."

This isn't even the first DNA to be found at El Mirón, either.

In 2025, researchers discovered both animal and human mitochondrial DNA in dirt samples that were dated between 46,000 and 21,000 years ago.

The animals and humans seem to have inhabited the cave at different times.

This new research goes even further and extracts nuclear DNA from the cave's sediment.

Mitochondrial DNA is only passed down through maternal lines, but nuclear DNA comes from both parents and contains more information on an individual's lineage.

This data can help scientists better understand whether or not Western and Eastern populations in Europe during the last ice age mixed, or if they stuck to their respective corners of the continent.

Where the new Ice Age DNA samples came from in southwestern Europe. 

(Gelabert et al., Science Advances, 2026)



To find out more about human migration at this time, lead author Pere Gelabert and colleagues compared the nuclear DNA found at El Mirón to the remains of an ancient woman in France, who lived roughly 31,000 years ago, and a tooth from northern Spain dated to around 25,000 years ago.

Both individuals appear to have had some Eastern ancestry, suggesting that human populations at both ends of Europe were interbreeding before the last glacial maximum.

But perhaps that mixing didn't last.

Human DNA from the El Mirón cave, which is roughly 22,000 years old, only shows signs of western ancestry.

"Crucially," the authors conclude, "… our genomic data argue against a major population replacement or discontinuity at this juncture."

Instead, the population in southwest Europe between 30,000 and 20,000 years ago seems to have remained relatively continuous.

The samples of ancient human DNA that scientists are working with from this time and place are still scarce, but sedaDNA techniques have already contributed greatly, practically doubling the evidence at hand.

"Future work integrating additional skeletal genomes and sedaDNA datasets will be essential to further resolve the processes that shaped the genetic landscape of Upper Paleolithic populations in Europe," conclude Gelabert and colleagues.

Our ancestors might have gone from ashes to dust, but they are still here with us after all.

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NASA’s Parker Solar Probe Discovers Something Unexpected Hidden in the Chaos of Space

By U. of Tokyo, Nov. 4, 2026

https://scitechdaily.com/nasas-parker-solar-probe-discovers-something-unexpected-hidden-in-the-chaos-of-space/

Artist’s illustration of NASA’s “Parker Solar Probe” mission. 

Credit: NASA/Johns Hopkins APL/Steve Gribben

NASA’s Parker Solar Probe has uncovered hidden order in space turbulence, a finding that could help scientists understand magnetic storms on Earth.

Smoke rising from an incense stick can begin as a thin, steady stream before curling and spreading unpredictably. The smoke makes turbulence in the air visible. Turbulence also occurs in space, where the moving material is plasma, an ionized gas containing electrically charged particles. Electric and magnetic fields strongly influence how those particles move, making this turbulence different from the movements of ordinary air.

Space plasma is also so dilute that its particles rarely collide, making it effectively collisionless. Physicists are still working to understand how turbulence develops under these conditions and how its energy is distributed. Measurements from NASA’s Parker Solar Probe have now revealed an organized pattern within that irregular activity.

Magnetic fields reverse rotation at smaller scales

At large scales, plasma behaves like a fluid, and turbulence develops through swirling motions called vortices and through electromagnetic waves. The fluctuations become random. At smaller scales, the dynamics of individual particles become important. These are different ways the same material behaves depending on the size of the disturbances being examined.

Using high-precision magnetic field and particle data from Parker Solar Probe, an international research team directly demonstrated, for the first time, that turbulent magnetic fields reverse their preferred direction of rotation across this transition. Picture the magnetic field’s direction as an arrow that can turn as the field fluctuates. Viewed looking radially away from the Sun, the fields preferentially rotate counterclockwise at larger scales. At smaller scales, they rotate clockwise.

Reversal of the field rotation from left-handed rotation (blue) to right-handed rotation (red), plotted on the frequency spectrum (y axis) against distance from the Sun x axis). Analysis based on the data from the Parker Solar Probe. A low frequency corresponds to a long wavelength in the spectrum. 

Credit: Iizawa et al., Astrophys. J. Lett., 2026



The reversal occurs at the wavelength, or spatial scale, where fluid-like behavior gives way to particle-like dynamics. Farther from the Sun, the reversal becomes more pronounced and shifts toward longer wavelengths, corresponding to larger spatial scales.

“We see a clear structure in the spectrum, even though the turbulence represents unstructured motions,” says Dr. Masatomi Iizawa of Technische Universität Braunschweig (TU Braunschweig), the article’s first author.

The study brought together researchers from the Institute of Theoretical Physics at TU Braunschweig and the University of Tokyo, in cooperation with Tohoku University, Kyushu University, Osaka University, and other research institutes. The collaboration spanned ten countries, and the results are published in The Astrophysical Journal Letters.

Turbulence shapes space weather

Dr. Yokoi of the University of Tokyo says, “The results are of great significance for both plasma physics and astrophysics.”

Plasma turbulence plays an important role in the solar wind, solar eruptions, and interplanetary space, as well as in Earth’s magnetosphere, the region dominated by our planet’s magnetic field. It also matters in accretion disks, where material orbits and moves inward toward a central object. In interplanetary space, turbulence can influence the shock waves and magnetic clouds produced by solar eruptions, making it an important factor in predicting geomagnetic storms.

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Researchers Discover Earth May Have Made Its Own Water 4.5 Billion Years Ago

By U. of New Mexico, Nov. 4, 2026

https://scitechdaily.com/researchers-discover-earth-may-have-made-its-own-water-4-5-billion-years-ago/

Artist’s illustration of early Earth, showing rocky debris raining through a scorching atmosphere onto a molten surface.

 Credit: University of New Mexico

Laboratory experiments suggest that rocky planets could generate their own water as they form, potentially giving distant worlds an essential ingredient for life.

Rocks, hydrogen gas, and intense heat might sound like an unlikely recipe for an ocean. Yet experiments suggest that these ingredients could have produced much of Earth’s water while the planet was still taking shape.

One leading explanation for Earth’s water involves small particles containing ice, known as icy pebbles. These formed in colder regions of the early solar system, where water could remain frozen, and may have carried that water to the growing Earth. Questions remain about how the particles traveled such long distances and whether those deliveries can fully explain Earth’s chemical composition.
Water in minutes from rock and hydrogen

Graduate student Susmita Garai led the new research with Zachary Sharp, professor and director of Earth and Planetary Sciences, and Peter Olson at the University of New Mexico. Their study, published in Nature Geoscience, investigated whether iron-bearing silicate rocks could react with atmospheric hydrogen under conditions resembling those of early planetary formation.

Experimental apparatus heating silicate rock samples. Credit: University of New Mexico



“In order to evaluate the possibility of ‘pebble’ rain’ being a source of water, we needed to construct and execute some very challenging high-temperature experiments. Dr. Garai’s efforts paid off mightily, as she found that water is produced in just minutes in the high-temperature environment of the Early Earth’s atmosphere,” Sharp said.

The researchers heated silicate rock samples to between 1,200 and 1,400 degrees Celsius, or about 2,192 to 2,552 degrees Fahrenheit, in experiments lasting from 15 minutes to three hours. Some samples were exposed to streams of hydrogen. Others were heated in helium for comparison, allowing the team to test hydrogen’s role in the reaction.

In the hydrogen experiments, nearly 80% of the iron oxide in the samples was converted into metallic iron, producing water vapor in the process. Hydrogen reacted with oxygen bound to iron in the rocks, leaving the iron as metal and forming water. The same reaction did not occur in helium.
Pebble rain could supply Earth’s oceans

“Previous ideas about the source of water to Earth rely on an external source, such as comets or meteorites. Here we show that virtually any Earth-sized planet should have water by this newly identified mechanism,” Sharp explained.

Results from the experiment. Left showcases the molten iron in silicate melt. Right shows the solid iron crystals in silicate melt.

 Credit: University of New Mexico



For this chemistry to supply a growing planet with water, rocky material, and hydrogen would need to meet under suitable conditions. That could happen during pebble accretion, a process in which small rocky particles accumulate to build a larger planetary body. Once the growing planet became sufficiently massive, it could develop a hot, high-pressure atmosphere rich in hydrogen. Silicate pebbles falling through that atmosphere could then undergo the water-producing reaction tested in the laboratory.

“We had suspected and hoped that we would produce iron metal and water in our reduction experiments, but we really had no way of knowing how fast and how much. We were quite surprised to find that extrapolation of our work suggests that hundreds of oceans worth of water were likely produced in this way. Looking out over a large body of water, it is hard to imagine that that water may have been produced 4 ½ billion years ago in a hell-like atmosphere, but it very well may have,” said Sharp.

AI generated illustration of pebble rain. 

Credit: University of New Mexico



Earth-sized worlds could make their own water

If comparable conditions developed around other rocky planets during their formation, the reaction could provide a widespread route to water on Earth-sized worlds beyond our solar system.

“The idea of pebble accretion is still relatively new. It’s only been around for the last decade. But it seems to solve many problems that exist with the existing paradigm for planet formation,” Sharp said. “And now we see that it also can explain why our planet is habitable. By extension, it is reasonable to expect that other Earth-sized bodies circling other stars would also have water and possibly life.”

The experiments demonstrate a potential mechanism for producing water during planetary formation. Determining how much of Earth’s water actually originated this way will require further research.

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Mosquitoes Are Picky Eaters – and Scientists Just Figured Out Why They Prefer Certain People

By Florida International U., Nov. 3, 2026

https://scitechdaily.com/mosquitoes-are-picky-eaters-and-scientists-just-figured-out-why-they-prefer-certain-people/

Few things are more annoying than mosquitoes. Their relentless buzzing, itchy bites, and knack for finding exposed skin can ruin an otherwise perfect evening outdoors. Worse still, these tiny pests can carry dangerous diseases, making them far more than just a nuisance. 

Credit: Shutterstock

Scientists have discovered that different mosquito species are attracted to distinct human scent signatures.

A person who attracts one mosquito species may be far less appealing to another. In a study involving 119 volunteers, researchers at Florida International University (FIU) found that three major disease-carrying mosquito species consistently preferred different people. Not a single participant was attractive to all three.

The findings, published in iScience, challenge the idea that some people are universally irresistible to mosquitoes. Instead, attraction appears to depend on how individual species detect the chemicals and microorganisms associated with human skin.

Different Mosquito Species Prefer Different Human Scents

The researchers examined three species responsible for spreading diseases such as dengue, Zika, yellow fever, and West Nile virus. Each responded to a different combination of biological signals.

Aedes aegypti, a mosquito that typically bites during the day, preferred people who wore no added fragrance and whose skin lacked certain volatile compounds. It also showed a slight preference for men. Another daytime feeder, Aedes albopictus (Asian tiger mosquito), was more attracted to people with elevated levels of ketones and plant-like chemicals naturally released by the skin.

Culex quinquefasciatus (southern house mosquito), which feeds after dark, responded more strongly to differences in the skin microbiome. This community of bacteria, fungi, and other microorganisms varies from person to person. Certain bacterial families were associated with increased mosquito attraction, while others appeared to discourage feeding.

A mosquito is examined under a microscope in the lab of FIU professor Matthew DeGennaro.

 Credit: Christopher Necuze/Florida International University



Human Body Chemistry Helps Explain Mosquito Preferences

Human scent contains more than 1,000 volatile organic compounds, many of which remain poorly understood. To investigate which biological characteristics influence mosquito attraction, the scientists collected odor and skin microbiome samples alongside their preference tests.

Led by Ph.D. student Kaylee Marrero, the study was the first to directly compare how multiple mosquito species respond to the same individuals. The researchers had not anticipated such clear differences between species.

“We didn’t expect the species to prefer different people when we started the study,” Marrero said. “Each species having a distinct microbial signature that they use as a cue was so surprising to me.”

The results suggest that mosquitoes have evolved different ways of detecting and interpreting the complex chemical signals produced by human skin.

“This connected so well with the differences in skin bacteria and odors,” said Matthew DeGennaro, a neurogeneticist who leads the research team and directs the Biomolecular Sciences Institute at FIU. “It is clear to me now that our skin microbiomes define our human odor signature. Each species found its own way to decode that signature.”

Toward More Targeted Mosquito Repellents

Understanding which chemicals attract or discourage individual mosquito species could help researchers develop repellents designed to interfere with specific scent signals rather than relying on a universal approach.

“Isolating the components of human odor that attract or repel mosquitoes could lead to novel strategies to combat vector-borne diseases,” DeGennaro said.

By identifying the chemical compounds and microbial signatures associated with each species, the researchers are establishing a foundation for more targeted mosquito control. Future repellents could potentially be tailored to the species responsible for transmitting diseases in particular regions, although further research will be needed to translate these findings into effective protection.

The Life of Earth

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120 Million Years Ago, Something Extraordinary Was Happening in Earth’s Oceans

By McGill U., Nov. 4, 2026

https://scitechdaily.com/120-million-years-ago-something-extraordinary-was-happening-in-earths-oceans/

Giant marine reptiles like long-necked plesiosaurs and marine crocodile relatives, as well as turtles, sharks, crustaceans and others, formed the Paja Biota, “one of the most ecologically complex marine communities found to date,” says researcher Dirley Cortés. 

Credit: Juan Giraldo

Colombia’s ancient seas supported an extraordinary diversity of top predators, offering clues to how life may undergo major evolutionary changes without a mass extinction.

Mass extinctions have reshaped life on Earth, but they may not be the only way ecosystems undergo dramatic evolutionary change.

Roughly 120 million years ago, the seas covering what is now central Colombia were home to an extraordinary mix of ancient Jurassic survivors and emerging Cretaceous predators. Fossils from this remarkably complex ecosystem suggest that some of evolution’s biggest turning points may unfold without a catastrophic mass extinction.

The Paja Biota’s predator-rich food web

The evidence comes from the Early Cretaceous Paja Formation near Villa de Leyva, Colombia, where the Centro de Investigaciones Paleontológicas (CIP) houses most of the formation’s fossils. The research at McGill University and CIP was conducted by PhD graduate Dirley Cortés and Professor Hans Larsson of McGill’s Department of Biology.

“This geological formation has produced an exceptionally rich fossil record that includes giant marine reptiles like long-necked plesiosaurs and marine crocodile relatives, as well as turtles, sharks, crustaceans and others,” Cortés explained. “Together, these animals formed the Paja Biota, one of the most ecologically complex marine communities found to date.”

Researcher Dirley Cortés at the CIP.

 Credit: Center for Paleontological Research



In a previous study, the researchers estimated the Paja Biota’s food web, the network of feeding relationships among its animals. They found it was among the most complex ever to have evolved, with a high diversity of apex predators, animals at the top of the food chain.

Ocean conditions may explain rare coexistence

“The Paja Formation records an extraordinary process in the history of life, when a ‘perfect storm’ of environmental factors we know to promote ecological complexity coincided with ancient lineages that were about to disappear. At the same time, new groups were beginning to flourish,” Larsson said.

The researchers suspect that greenhouse temperatures, high sea levels, and nutrient-rich coastal waters helped support this exceptional biodiversity and biological transition. New marine connections between the eastern Pacific and early Atlantic oceans through what is now Colombia were probably also part of that rare convergence. Many of these same factors help drive biodiversity today, they noted.

The team identified the pattern in the Early Cretaceous Paja Formation near Villa de Leyva, Colombia, where the CIP houses most of its fossils.

 Credit: Center for Paleontological Research



Testing whether Biotic Inflections happened elsewhere

Cortés and Larsson propose calling the pattern a “Biotic Inflection,” a period when many evolutionary lineages nearing extinction coexist with newly emerging groups that later diversify.

“I think we’ve discovered a new model of global biodiversity change. Now we’ll need to see just how widespread this could be in Earth’s history and how we can quantify its impacts,” Larsson said.

Testing the proposal will require additional fossil sampling, more precise dating, and comparisons with deposits elsewhere in the world. Those investigations would help establish how widespread the Biotic Inflection pattern was and when similar events may have occurred in Earth’s history.

The Life of Earth

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Earth’s Oceans Were Slowly Suffocating Millions of Years Before a Devastating Mass Extinction

By Virginia Tech, Nov. 2, 2026

https://scitechdaily.com/earths-oceans-were-slowly-suffocating-millions-of-years-before-a-devastating-mass-extinction/

Fossilized shells from the sedimentary rock layer. 

Credit: Ben Gill

As today’s oceans lose oxygen, Alaskan rocks trace a similar decline that began millions of years before the end-Triassic mass extinction.

Dinosaurs survived the end-Triassic mass extinction 201 million years ago, but roughly 60 percent of Earth’s species did not. New evidence from Virginia Tech geologists suggests that the crisis in the oceans began about 8 million years earlier, when oxygen levels in shallow waters started to decline.

Scientists have long linked the extinction to enormous volcanic eruptions that tore apart landmasses, warmed the planet, and triggered widespread environmental changes. As temperatures rise, rocks break down faster, releasing nutrients that contribute to increasing ocean acidity. Warmer seawater also holds less dissolved oxygen, creating conditions that can lead to oxygen-depleted dead zones where marine organisms struggle to survive.

The combination of rising acidity and falling oxygen is “kind of like a one-two punch,” said geochemist Ben Gill. “It wouldn’t have been a very happy place to be.”

Although scientists had previously found evidence of widespread marine oxygen loss around the end-Triassic extinction, much of it came from a limited geographic area. Researchers still lacked a clear understanding of when the decline began and how extensively it affected the oceans. Recent studies had also raised the possibility that environmental conditions started deteriorating far earlier than previously believed.

“It’s a 200-million-year-old cold case,” said Kayla McCabe, a former Virginia Tech geosciences graduate student and first author of the study, published in Communications Earth & Environment.

Alaska’s rocks reveal a prolonged oxygen crisis

To investigate, McCabe and her colleagues turned to sedimentary rocks at Grotto Creek in Alaska’s Wrangell–St. Elias National Park. The remote location is accessible only by small aircraft, and the team traveled there in 2017, 2019, and 2022 to collect evidence of ancient ocean conditions.

Sedimentary rocks form as layers of material accumulate over time, preserving chemical traces of the environments in which they were deposited. By comparing layers formed before, during, and after the extinction, the researchers could reconstruct how oxygen conditions changed across millions of years.

Members of a field team examine an outcrop of rock layers in Grotto Creek in Alaska’s Wrangell–St. Elias National Park in 2019. 

Credit: Ben Gill



The geochemical analyses revealed a prolonged deterioration rather than a sudden collapse. The earlier decline likely placed marine ecosystems under stress long before the main extinction event. Conditions then worsened considerably during the extinction itself, with the rock record showing a much more severe loss of oxygen. The findings indicate that oxygen starvation became a major contributor to the disappearance of marine species.

The earliest oxygen loss remains unexplained

What triggered the initial decline remains uncertain. The massive volcanic eruptions associated with the end-Triassic extinction have long been considered a major cause of the environmental catastrophe, but the newly identified timeline raises questions about what was happening millions of years beforehand.

“There’s evidence of another volcanic province that roughly lines up with this time interval,” Gill said. “But we’re in the very beginning of trying to understand what happened.”

Ancient oxygen losses echo in modern oceans

The ancient rock record also offers a way to examine the potential consequences of environmental changes unfolding today. Modern oceans are experiencing rising temperatures, acidification, and declining oxygen levels. Ocean deoxygenation is an ongoing concern, including in coastal environments such as the Chesapeake Bay.

Although the ancient and modern circumstances are different, understanding how warming and oxygen depletion affected marine life in the past could help scientists anticipate the combined pressures facing ocean ecosystems today.

“Earth has run this experiment in the past. We have evidence that the climate gets warmer, and then all these other knock-on effects come afterwards,” Gill said. “It gives us some sense of what we can expect to happen.”

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Scientists Witness a Mysterious Sexual Bond Between a Bull And a Male Donkey

03 Nov. 2026, By P. Dockrill

https://www.sciencealert.com/scientists-witness-a-mysterious-sexual-bond-between-a-bull-and-a-male-donkey

Achille with Patroclo. 

(André B. da Cruz)

The heart wants what the heart wants.

At least, that's one way of looking at an extraordinary relationship scientists discovered by chance during fieldwork in Ethiopia.

Over a series of observations, researchers documented an unusual sexual bond between a male donkey and a bull.

The observations, reported in Current Biology, show animal sexual behavior can be a more complex social phenomenon than we might realize, the team says.

"Nature does not always respect the boundaries we draw around it," ethologist Elisabetta Palagi from the University of Pisa in Italy told ScienceAlert.

"Animal behavior is not a picture painted in black and white: It uses the whole palette, with all the colors of the rainbow."

While same-sex sexual behavior (SSSB) is a widespread behavior among animals, observations of sex between animals of different species are much rarer.

Editor's note: The video below shows footage of the bull mounting the donkey.

https://www.youtube.com/watch?v=WmusyMW6zis

Yet the interactions observed by Palagi's team between Achille (a bull) and Patroclo (a male donkey) might be something even rarer still – a bond that possibly transcended the sexual encounters they shared.

"Both animals had access to other potential partners, including individuals of their own species and of both sexes," Palagi said.

"Yet they repeatedly sought each other out."

The research team had traveled to the Ethiopian highlands to study gelada monkeys when they noticed by accident the interactions between Achille and Patroclo in a nearby grazing area.

Over a number of days, Achille was seen mounting Patroclo. Mounting was documented 51 times, with 34 of the events resulting in intromission (penile penetration).

Editor's note: Graphic image below of the bull mounting the donkey.

When Achille tried the same thing with another male donkey in the pasture, the donkey showed clear avoidance behaviors, including a display of threatening facial expressions (ear flattening).

In contrast, Patroclo never avoided or kicked away Achille, but instead appeared to present his hindquarters to the bull, and both animals engaged in other acts that caught the researchers' attention.

Achille mounting Patroclo.

 (Martina Francesconi, University of Pisa)



"Achille and Patroclo were more likely to exchange affiliative behaviors, such as licking, rubbing and nuzzling, with each other than with other animals, and these interactions lasted longer. They also spent most of their observed time close together," Palagi said.

"The sexual interactions were one component of a much broader, selective relationship."

According to the researchers, pre-mounting behaviors (involving acts such as licking and nuzzling) are not unexpected between animals, as they may help facilitate mounting.

But Patroclo and Achille's behavior was perhaps unusual, in that they engaged in post-mounting interactions much more often than any foreplay, suggesting there was more to their relationship than sex alone.

"Although interpreting this behavior is challenging, the interactions observed between Achille and Patroclo, embedded in repeated, reciprocal, and mutual affiliative interactions, may also function as a signal of relationship quality," the researchers write in their paper.

"Rather than being solely attributable to sexual arousal, these interactions appear to play a role in prolonging the social interaction beyond the sexual act."

On another occasion, when Achille mounted another donkey, Patroclo moved in close, as if to prevent further interactions between them, and Achille ended up interacting with Patroclo instead, including body licking.


According to Palagi, this apparent selectivity and the consistency of their association were the most surprising part of the research, especially since the animals belonged to different owners and spent their nights apart, only encountering each other during daily grazing.

"The mounting initially attracted our attention, but their repeated preference for each other's company became the most compelling part of the story," Palagi told ScienceAlert.

"Patroclo's behavior was particularly striking… His participation made the relationship especially intriguing."

According to the researchers, Achille and Patroclo's interactions appear to be the first documented case of a sustained same-sex sexual relationship between a bull and a donkey.

While we can't know exactly what the relationship meant to them – and need to be careful not to interpret their interactions through an anthropomorphic lens – it's clear something was going on here, suggestive of a social bond that crossed a boundary between species.

Whether that bond still exists is uncertain. After the study, Achille and Patroclo were moved to different grazing areas.

The researchers hope to return to see if the animals resume their activities, and to investigate whether similar relationships are occurring between species more often than we realize.

"Unusual behavior can remain anecdotal simply because nobody has the opportunity to document it systematically," Palagi said.

"Nature's full palette becomes visible only when we are willing to notice the unexpected."

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Scientists Discover That a Giant Bird Thought Extinct for Thousands of Years Never Actually Disappeared

By Bournemouth U., Nov. 2, 2026

https://scitechdaily.com/scientists-discover-that-a-giant-bird-thought-extinct-for-thousands-of-years-never-actually-disappeared/

The common crane (pictured above) is the same species as a prehistoric giant crane once thought to be extinct, according to new ancient DNA research. 

Credit: Shutterstock

Ancient DNA analysis has challenged a 150-year-old belief about a giant bird thought to have disappeared after the last Ice Age.

For more than 150 years, scientists believed that enormous crane bones found in European caves belonged to a giant bird species that disappeared after the last Ice Age. Now, ancient DNA has overturned that identification, revealing that the supposedly extinct bird was actually a larger version of a species still living in Europe today.

Researchers at Bournemouth University (BU) found that the fossils attributed to Grus primigenia belonged to the common crane. Their findings also raise questions about whether other prehistoric birds classified as extinct species were simply larger forms of birds that survive today.

Ancient DNA Solves a 150-Year-Old Mystery

The mystery began in the 19th century when French biologist Alphonse Milne-Edwards examined unusually large crane bones discovered in caves in southern France. Believing they represented a distinct species, he named the bird Grus primigenia. The remains dated to the end of the last Ice Age and were long considered evidence of an extinct giant crane.

To investigate the bird’s identity, a team led by Dr. John Stewart, Professor of Evolutionary Paleoecology at BU, analyzed ancient DNA from 18 crane bones recovered across England, Wales, France, Germany, and the Balearic Islands. Working with the Centre for Palaeogenetics in Stockholm, Sweden, the researchers used genetic evidence to determine which species the bones belonged to.

“Previous studies had merely used the size and shape of the bones to attempt to understand these large birds. The use of DNA analysis has given us a more accurate picture of what they represent,” Stewart explained.

Why Scientists Mistook the Cranes for an Extinct Species

The genetic findings indicate that the oversized fossils belonged to common cranes rather than a separate extinct species. Stewart believes differences in body size between male and female cranes may have contributed to the original misidentification.

“We suspected that these large cranes were not extinct and instead represented larger, modern European common cranes. We believe that the reason for the mistaken identity was that cranes have large males and smaller females, and we think this contributed to previous speculation that there were two different species: the living, common crane we see today and the extinct, larger species,” Stewart said.

What Caused Ancient Cranes to Shrink?

Although the DNA evidence clarifies the birds’ identity, it leaves another question unanswered: Why were some prehistoric common cranes considerably larger than those living today?

“The challenge going forward is to investigate the reason for the cranes decrease in size. Wetland drainage and human land use changes are what we suspect, but more work is needed to resolve that,” Stewart said.

The researchers plan to investigate whether changes in wetland habitats and human land use contributed to the reduction in crane body size. These remain possible explanations rather than established causes.

Could Other Supposedly Extinct Birds Still Exist?

The findings suggest that some prehistoric bird species identified primarily through fossil measurements may need to be reconsidered. Differences in bone size do not necessarily indicate separate species, and ancient DNA could help determine whether other supposedly extinct birds were actually larger or smaller populations of surviving species.

“While it is true that many species of birds are vulnerable to human actions today, it may be that we have overestimated the number of extinctions in the past,” Stewart said.

“Some of these may instead represent size changes to living species,” he concluded.

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Human Bodies Are Producing Two Billion Tons of CO2 a Year

By U. of Bath, Nov. 2, 2026

https://scitechdaily.com/human-bodies-are-producing-two-billion-tons-of-co2-a-year/

Scientists have uncovered a largely overlooked component of the global carbon cycle, revealing how population changes are reshaping the amount of CO2 humans produce. 

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A new study reveals that the amount of carbon dioxide produced by human metabolism has increased dramatically over three decades.

The carbon dioxide produced by human bodies as they convert food into energy increased by 74% over three decades, according to a University of Bath-led study. By 2015, the global total had reached an estimated 2.05 billion metric tons (2.26 billion U.S. tons) annually, highlighting a substantial component of the Earth’s carbon cycle that scientists had not previously quantified on this scale.

Unlike emissions from burning fossil fuels, the CO2 humans exhale largely comes from carbon recently absorbed from the atmosphere by plants and transferred through food. Burning coal, oil, and natural gas releases carbon that has been stored underground for millions of years, adding it to the active carbon cycle.

Population Growth Drove Most of the Increase

Published in The Lancet Planetary Health, the study found that annual CO2 production from human metabolism rose from 1.18 billion metric tons (1.30 billion U.S. tons) in 1985 to 2.05 billion metric tons (2.26 billion U.S. tons) in 2015. More than 60% of that increase was attributable to population growth rather than a substantial rise in the amount produced by each individual.

To estimate global emissions from metabolism, the researchers analyzed thousands of real-world measurements of CO2 production in people ranging from infants to older adults. They combined these findings with worldwide population and body weight data to calculate how human metabolic activity changed over time.

Professor Javier Gonzalez, who led the research at the University of Bath’s Centre for Exercise, Nutrition and Metabolism, explained:

“We all produce carbon dioxide simply by turning food into energy, but until now we haven’t had a good idea how much that adds up to worldwide.

Improving Our Understanding of the Carbon Cycle

“What we’ve found is that the increase is mainly because there are more of us. This gives scientists one more piece of the puzzle when working out where carbon comes from and where it goes. Ultimately, this information can help scientists more accurately predict how effective carbon reduction strategies may be.”

Human metabolism contributes to the continuous movement of carbon through the environment, particularly in densely populated cities. Accounting for that activity could help researchers develop more accurate carbon budgets and better assess the effects of strategies designed to reduce emissions.

Why Human Breathing Is Not Driving Climate Change

The researchers emphasize that their findings do not suggest people should exercise less, change their diets, or attempt to reduce the carbon dioxide they breathe out. The purpose is to improve scientific measurements of carbon movement, not identify respiration as a contributor to fossil fuel emissions.

Gonzalez stressed the distinction: “The important thing is that the carbon dioxide we breathe out is not the same as burning fossil fuels. We’re not saying that breathing is driving climate change.

“What this study does is give us a much clearer picture of how much CO2 people produce around the world, and how that is changing as the population grows. This understanding can help improve the accuracy predictions of carbon reduction programs.”

The Life of Earth

https://chuckincardinal.blogspot.com/

Depression Symptoms Improved in Just 48 Hours After a Single Psychedelic Dose

By Karolinska Inst., Nov. 1, 2026

https://scitechdaily.com/depression-symptoms-improved-in-just-48-hours-after-a-single-psychedelic-dose/

Psilocybin is a naturally occurring psychedelic compound found in certain species of mushrooms, commonly known as magic mushrooms. In the body, it is converted into psilocin, which acts on serotonin receptors in the brain, altering perception, mood, and thought processes. 

Credit: Shutterstock

A single dose of psilocybin produced rapid antidepressant effects in a small Swedish clinical trial, with improvements lasting for weeks.

A single dose of psilocybin, the psychedelic compound found in magic mushrooms, produced rapid improvements in depression symptoms in a small Swedish clinical trial. After six weeks, 53% of participants who received psilocybin were in remission, compared with just 6% of those given a placebo.

Some participants reported improvements within two days, and the antidepressant effects persisted for more than three months in self-reported assessments. The findings come from Sweden’s first randomized, double-blind trial of psilocybin for depression, conducted by researchers at Karolinska Institutet and published in JAMA Network Open.

Hampus Yngwe 

Credit: Photo: Stefan Zimmerman



Testing Psilocybin for Common Depression

Selective serotonin reuptake inhibitors (SSRIs) are among the most widely prescribed treatments for depression, but they can take several weeks to work, cause unwanted side effects, and provide insufficient relief for some patients. Previous research has suggested that psilocybin may act more quickly, although much of that work has focused on treatment-resistant depression or depression associated with cancer.

The new phase 2 trial investigated whether psilocybin could also help people with more common forms of recurrent depression. Researchers enrolled 35 adults between the ages of 20 and 65 who had moderate to severe symptoms. Participants were randomly assigned to receive either 25 milligrams of psilocybin or niacin, a vitamin used as an active placebo because it produces noticeable physical sensations.

Both groups received psychotherapeutic support across five sessions before, during, and after treatment. During the dosing session, participants wore eye masks, listened to music through headphones, and were encouraged to direct their attention inward.

Depression Symptoms Improved Within Days

Researchers measured depression severity using the MADRS (Montgomery–Åsberg Depression Rating Scale), with assessments conducted by clinicians who did not know which treatment each participant had received.

Eight days after treatment, depression scores had fallen by an average of 9.7 points in the psilocybin group, compared with 2.4 points in the placebo group. The 7.3-point difference was statistically significant and considered clinically meaningful. The advantage remained evident at assessments conducted 15 and 42 days after treatment, while participants’ own ratings indicated improvement as early as the second day.

“Our results suggest that psilocybin can provide rapid, clinically meaningful improvement in depression and may serve as an alternative to standard treatment when fast symptom reduction is important,” says lead author Hampus Yngwe, consultant psychiatrist and PhD student at the Department of Clinical Neuroscience, Karolinska Institutet.

Long-Term Effectiveness Remains Uncertain

Although the initial results favored psilocybin, the difference between the groups was no longer statistically confirmed after one year. At that point, 53% of participants in the psilocybin group remained in remission, but many people who had received the placebo had also recovered.

Johan Lundberg 

Credit: Photo: Stefan Zimmerman



“However, the long-term effects are uncertain. Repeated treatments may be needed to prevent relapse. This needs to be investigated in larger studies.”

The findings suggest that a single supervised dose may provide relatively rapid symptom relief for some patients, but the small trial cannot establish how consistently those benefits will last or whether additional doses would improve long-term outcomes.

Side Effects and the Challenge of Blinding

Psilocybin was generally well tolerated, with most reported side effects being mild or moderate and temporary. However, two participants who received the psychedelic experienced severe, persistent anxiety that required medical attention.

“It is important to emphasize that the treatment is not risk-free and that some patients may need extra support,” says Johan Lundberg, professor at the Department of Clinical Neuroscience and the Centre for Psychiatry Research, Karolinska Institutet, who led the study.

Another limitation involved the difficulty of keeping participants unaware of their assigned treatment. Psychedelics produce distinctive psychological effects, and almost everyone in the trial correctly guessed whether they had received psilocybin or the placebo. Such awareness can influence expectations and make it harder to determine how much improvement comes from the drug itself.

“We want to understand how factors such as treatment expectations and lack of blinding affect the results, as previous studies may have exaggerated the treatment effects,” says Hampus Yngwe.

Investigating How Psilocybin Changes the Brain

Researchers are now turning to biological measurements collected during the trial to investigate how psilocybin might influence depression. Their next analyses will examine PET brain scans alongside blood and cerebrospinal fluid samples obtained before and after treatment.

One area of interest is synaptic density, which reflects the number of connections through which nerve cells communicate. Depression has been associated with disrupted communication between brain regions, while preclinical studies suggest that psychedelics may promote the growth of synaptic connections. Whether comparable changes occur in people receiving psilocybin remains an open question.

“Research suggests that the interaction between parts of the brain is impaired in depression and that this may be linked to changes in the connections between nerve cells, known as synapses. In preclinical studies, psychedelics have been shown to stimulate synaptic growth. We therefore want to investigate whether psilocybin alters synaptic density in the brain,” concludes Hampus Yngwe.

The Life of Earth

https://chuckincardinal.blogspot.com/

Aphantasia: Some People Can't Picture Things While Awake, But See Them in Dreams

02 Nov. 2026, By E. Öz

https://www.sciencealert.com/aphantasia-some-people-cant-picture-things-while-awake-but-see-them-in-dreams

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Picture someone you know well. You might be able to bring their face to mind, perhaps their smile or the way their hair falls. For some people, that familiar face never becomes a mental picture, however hard they try.

When they fall asleep, this can change. Faces and places may appear in their dreams, even though they cannot deliberately picture them during the day.

What allows those images to appear during sleep?

The inability to picture things at will is known as aphantasia. A study published in Scientific Reports explored the dreams of people who have it and found that the relationship between waking imagination and dreaming varies considerably from person to person.

The researchers looked beyond images, asking about sounds, smells, tastes, touch, the feeling of movement, and inner speech, the experience of hearing words in your mind.

Some people described similar sensory experiences while dreaming and imagining things awake. Others reported sensations in dreams that they could not deliberately summon during waking life.

The question had a personal beginning. Two of the researchers, Derek Arnold and Loren Bouyer of the University of Queensland in Australia, describe having lifelong aphantasia. Their dreams are not alike, and each felt that the sensations in their dreams reflected those they could imagine during the day.

They had previously described how their imaginations differ. Arnold can imagine sounds, while Bouyer can imagine sensations of touch. Neither can voluntarily form mental pictures.

Working with Merlin Monzel of the University of Bonn in Germany, they investigated how these experiences varied among a larger group.

The team analyzed online questionnaire responses from 205 people. Scores measuring visual imagination placed 84 participants in a visual aphantasia group and 121 in a comparison group.

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Participants considered situations that might bring different senses to mind, such as remembering a social gathering. They ranked the imagined sensations they experienced and answered questions about everyday habits, including mentally rehearsing conversations or imagining how a movement would feel.

They also reported how often different sensations appeared in their dreams, with an option to say they were unsure.

Within the aphantasia group, 46 percent reported always having visual experiences in their dreams. About 8 percent reported never having them. Nobody in the comparison group reported experiencing visual dreams.

Among participants in the aphantasia group, the researchers found no evidence that stronger waking visualization went along with more frequent visual dreaming.

The connections were clearer for sounds and inner speech. Participants who reported these experiences more often in dreams also tended to report them more often while awake, although the associations were generally weak to moderate.

People in the aphantasia group who often heard sounds and conversations while dreaming also tended to report more frequent use of imagined sounds and inner speech in daily life, such as mentally rehearsing conversations before speaking.

Across the three questionnaires, participants were consistent in how closely their waking imagination matched their dreams. Some repeatedly reported a close match, while others described substantial differences.

Why a sensation would be available during sleep but not on demand while awake is still unclear. One possible explanation involves how brain regions involved in imagination work together. The researchers suggest that difficulties coordinating this activity might continue during sleep for some people, while changing for others.

Comparing brain activity in people with these different experiences could help test that idea. It could also reveal whether similar processes produce imagined sensations during waking life and dreams.

The study did not measure brain activity, so that explanation remains untested. The findings rely on participants describing their experiences and remembering their dreams. Those in the aphantasia group were also more likely to be unsure whether particular sensations occurred in their dreams. The group included some people with weak visual imagination alongside those reporting none.

Future sleep studies could bring researchers closer to the experience itself by waking participants immediately after dreams and asking what they remember.

Some people with aphantasia report images and sounds in dreams that they cannot call up while awake. For others, the sensations missing from waking imagination are also absent from their dreams.

The Life of Earth

https://chuckincardinal.blogspot.com/

Just 30 Minutes in a Sauna Triggers an Immediate Immune Response

01 Nov. 2026, By C. Cassella

https://www.sciencealert.com/just-30-minutes-in-a-sauna-triggers-an-immediate-immune-response

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Some people swear by a sauna session. They claim that sitting and sweating in a hot room rejuvenates them.

But for such a popular trend, the scientific evidence to support that feeling is surprisingly scarce.

Researchers in Finland have now found evidence that a single sauna session can have an immediate impact on the immune system at a cellular level.

In a small experiment, just 30 minutes in a Finnish sauna – with hot yet dry heat – triggered a significant increase in circulating white blood cells.

These crucial immune cells help defend the body against pathogens, and they often increase after exercise.

Simply sitting in a sauna could stimulate a similar stress response, and it could have benefits for the immune system.

The results are published in Temperature.

"This may indicate that sauna bathing mobilizes additional white blood cells into the bloodstream from tissues, where they are then redeposited after the session," speculates exercise scientist Ilkka Heinonen from the University of Turku in Finland.

"This kind of periodic release of white blood cells into the bloodstream is beneficial, as once they leave their storage sites, they are better able to patrol the body and respond to pathogens."

(Blasius Erlinger/The Image Bank/Getty Images)



In the experiment, 51 middle-aged men and women took part in a traditional Finnish sauna session.

This included sitting in a room at around 73° Celsius (163° Fahrenheit) for 30 minutes, with a cold shower halfway through.

Immediately after the session, a whole host of white blood cells appeared to be mobilized in the blood of participants compared to before the sauna session.

This included an increase in neutrophils, which are first responders, and lymphocytes, which help build immune memory.

There was also an increase in the combined count of monocytes, which engulf pathogens and debris, and eosinophils and basophils, which are both linked to inflammatory responses.

Levels of immune messenger proteins called cytokines, on the other hand, barely shifted, on average, although a few did increase with body temperature.

Thirty minutes after the sauna session, however, this apparent immune surge had mostly dropped off again.

Most of the white blood cell increases had disappeared, but some monocytes lingered.

Researchers only analyzed participants' bloodwork up to 30 minutes after the sauna session, so it is unclear how their immune cells might change over longer periods of time or how that might impact their risk of getting sick.

But some observational studies in the past have found that frequent sauna bathing is associated with a lower risk of some illnesses, like pneumonia.

What's more, other experiments have shown that hot baths can lower your blood pressure and significantly increase red blood cells that carry oxygen.

Bathing in heat seems to produce similar physiological responses to what occurs during exercise, and these cardiovascular outcomes are linked to improved immune function.

That said, vigorous exercise can also backfire, temporarily weakening the immune system, so there's reason to tread cautiously.

Extreme heat isn't something to mess with.

Despite growing global interest in hot and cold therapy, scientists still know remarkably little about how the body copes with extreme temperatures, and what that means for our short-term or long-term health.

The recent experiment in Finland is limited in what it can tell us.

Researchers did not measure specific immune cell subsets, like T cells or natural killer cells, which could have provided more insight into how a sauna actually impacts immune function.

In 2023, for instance, a study reported that Finnish sauna sessions altered T cells and natural killer cells, but only when the sessions were repeated.

What's more, the impact was different depending on whether the participants were trained sauna-goers or not.

In this experiment, repeated sauna exposure increased white blood cell counts in trained participants, but it reduced some T cells in untrained participants.

That study, however, only analyzed healthy young men, which limits how these results can be generalized to others.

For now, all we can say is that it looks increasingly like bathing in heat can trigger a temporary change to immune cells.

Beyond that, it's all guesswork.

Plus, it's good to remember that just like cold therapy, hot therapy might also come with risks…

The Life of Earth

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