Avocados Switch Sex on a Daily Basis, And Researchers Finally Know How

08 Aug. 2026, By I. FARKAS

https://www.sciencealert.com/avocados-switch-sex-on-a-daily-basis-and-researchers-finally-know-how

Persea americana avocado fruit, as analyzed in this research.

  (B.navez/Wikimedia Commons)

At some point in evolutionary history, possibly around 400 million years ago, things started having sex.

This adaptational (and sensual) advance introduced multiple benefits by allowing increased gene sharing, thereby helping to prune deleterious mutations and boost general fitness.

Avocado trees also ostensibly like to have sex, but face a problem: Each tree's flowers have both female and male reproductive organs, so they must somehow avoid self-pollination to derive such sexual benefits.

They do this through a clever evolutionary trick called temporal dichogamy, where the flowers of avocado trees (and many other angiosperms) functionally 'switch sexes' each day.

Yet the underlying genetic basis has fascinated and frustrated botanists and growers for over a century.

In a new study, a team of ecologists and agricultural engineers combined field observations with genetic analyses to finally crack the conundrum of avocado sexuality, revealing their dichogamy-defining gene variants.

"Our study provides a genetic explanation for a century-old mystery of avocado pollination," says Jeffrey Groh, an evolutionary geneticist now at the University of California (UC) Berkeley.

At any moment, an avocado tree may be functionally female or male, with its flowers either receiving or releasing pollen, respectively.

They also display complementary sexual schedules.

"A-type" avocado trees open their female flowers in the morning and their male flowers in the afternoon, while a basically equal population of "B-type" avocado trees do the opposite – avoiding perils of self-pollination.

An image showing an avocado tree's flowers being both open and closed.

  (Jeffrey Groh/UC Davis)



"Flowers are not just static decorations; they are highly evolved and dynamic structures. We can see this in the pulsating rhythm of avocado flowers opening and closing throughout the day," says Groh.

"Through the power of genetics, we can detect traces of this rhythm far into the ancient past."

To approximate an avocado gender reveal, the researchers mapped the genomes of hundreds of avocado trees in varying detail, including the activity of genes at specific times of the day.

They also conducted an avocado 'sex watch,' spending days and nights documenting the hour-by-hour opening and closing of thousands of flowers that react to tiny changes in temperature and light.

The researchers discovered evidence that the activity of a single gene, named SDMYB, oscillates like a clock and controls A- or B-type flowering behaviors.

Researchers tracked the flowering phases of A- and B-type avocado plants over consecutive days. 

Flowers of Persea americana in the female (B) and male phase (C) are also shown. (Groh et al., PNAS, 2026)

The SDMYB gene comes in two variants, known as alleles. A-type trees carry one of each gene variant, while B-type trees hold two copies of the recessive version, providing a revelation that promises to supercharge avocado science.

"These genetic markers will greatly speed up avocado breeding and research," explains Graham Coop, an evolutionary geneticist and professor of evolution and ecology at UC Davis, as well as the study's senior author.

"This has been a major impediment for avocado breeders. Previously, you could not tell whether a plant was an A- or a B- type until it flowered, and avocado plants may take up to 10 or 15 years to flower in the first place."

Unveiling these genetic blueprints, which appear to have emerged more than 42 million years ago, can pay immediate dividends.

"This is something we can begin using right away," says Marllon Soares dos Santos, an agricultural engineer at UC Riverside and one of the study's co-authors.

For example, California avocado growers may stock 10 percent of an orchard with B-type pollinizer trees to help their neighboring A-type trees produce more fruit.

Yet the fruit of B-type trees is commercially undesirable, unlike the world's favorite, supermarket-stocked Hass avocado, an A-type treat.

"Instead of planting hundreds of seedlings and waiting years to see which flower type they become," Soares Dos Santos explains, "we can make those decisions at the beginning. That makes breeding much more efficient."

So, given the creative cultivation of other popular plants, like grapes, might we be making cotton-candy-flavored guacamole anytime soon?

Alas, gene editing applications may remain many years away. But the genetic markers illuminated in this work will allow breeders to select the plants they want without having to wait for them to flower – saving them time, labor, and orchard space.

"People have wondered about this trait since avocado breeding began in California," concludes Eric Focht, a botany-and-plant-sciences researcher at UCR and one of the study's co-authors.

"Now we finally understand the genetics behind it, and we can use that knowledge to build the next generation of avocados."

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Meet the 30-Million-Year-Old Dog That Climbed Trees Instead of Chasing Sticks

BY M. SHERBURNE, U. OF MICHIGAN, AUG. 6, 2026

https://scitechdaily.com/meet-the-30-million-year-old-dog-that-climbed-trees-instead-of-chasing-sticks/

Anne Kort, an assistant professor in the Museum of Paleontology and a Michigan Society of Fellows postdoctoral scholar, excavates a horse leg bone at John Day Fossil Beds National Monument in Oregon.

 Credit: Nicholas Famoso, John Day Fossil Beds National Monument

A nearly complete fossil shows that one early dog combined climbing ability with a body unlike those of modern running canids.

For more than 30 years, a fossil roughly 30 million years old remained sealed inside rock in an Oregon museum collection. When paleontologists first recovered it, they believed it might belong to an oreodont, an abundant group of extinct mammals related to sheep, camels and pigs.

Researchers later recognized the specimen as an early dog. University of Michigan paleontologist Anne Kort has now identified it as one of the most complete pre-Ice Age dog fossils ever found in North America. The animal belongs to Mesocyon coryphaeus, a species named in 1879 that had previously been known only from individual skulls.

Kort was asked to study and describe the fossil for a special issue of the Journal of Paleontology marking the 50th anniversary of John Day Fossil Beds National Monument, known as JODA. The specimen was discovered in the late 1980s on Bureau of Land Management property near the Oregon monument.

Kaori Chambers, University of Michigan graduate student in ecology and evolutionary biology, created an artistic representation of Mesocyon coryphaeus. U-M paleontologist Anne Kort identified a fossil as one of the most complete Mesocyon coryphaeus specimens found yet. The specimen was a fossil dog the size of a coyote. 

Credit: Kaori Chambers, University of Michigan



Paleontologists removed the fossil together with the rock surrounding it, then enclosed the entire block in a protective plaster jacket. During the 1990s, researchers separated the skull for display and determined that it came from a dog. In 2012, park paleontologists, including study coauthor Jennifer Cavin prepared the rest of the skeleton and recognized how much of the animal had survived.

“They thought at first it was an oreodont, which we like to call sheep-camel-pigs,” said Kort, who was a postdoctoral scholar at U-M’s Museum of Paleontology. “This was the most magical, fun project to just be handed on a silver platter.”
Multiple clues confirm an early dog

Paleontologists usually identify an ancient dog by comparing its skull, teeth and other anatomical features with those of known canid fossils. This specimen contained another revealing clue: a hereditary bone growth at the end of the wrist called an osteochondroma. The same condition occurs in approximately 60% of the earliest known dog fossils.

University of Michigan paleontologist Anne Kort identified a fossil as one of the most complete Mesocyon coryphaeus specimens found yet. The specimen, a fossil dog the size of a coyote, had an elbow joint suggesting it could climb and grapple, according to Kort. 

Credit: Anne Kort, University of Michigan



“It’s just this really cool direct hereditary link that we wouldn’t normally find,” Kort said. “This is another line of evidence, and that gives you an idea of how great this fossil is.”

Nearly the entire skeleton is preserved. Only the tail and portions of the hands and feet are missing. Its completeness also allowed the researchers to determine the animal’s sex without relying on indirect anatomical estimates.

“The other fun thing is, it even had the baculum, so, the penis bone,” Kort said. “That means we definitely know this was a male.”
This dog had not mastered running

According to Kort, dogs originated in North America approximately 40 million years ago. Their common ancestor was a canid called Hesperocyon. At that time, much of the continent was covered by dense forests resembling rainforests, and Hesperocyon was probably a “pretty good climber,” unlike dogs living today, Kort says.

A fossil of Mesocyon coryphaeus was found on Bureau of Land Management land in the 1980s, near the John Day Fossil Beds National Monument. 

Credit: Image courtesy of National Park Service. Mural created by Roger Witter




Mesocyon appeared about 10 million years later as the global climate cooled. Dense forests were gradually replaced by more open woodlands and, in some places, shrublands. Kort examined the unusually complete skeleton to determine whether Mesocyon had already developed the running adaptations seen in modern dogs.

“The answer is pretty definitely no,” said Kort, who studies the interaction between environment and running adaptations in mammals. “Mesocyon also just has more robust bones in general. It’s shorter and stockier.”

The shape of the elbow joint indicates that Mesocyon could rotate its forearms, an ability that would have helped it grapple and climb, Kort says. The animal also retained a large first toe, represented by the dew claw in modern dogs. This anatomy suggests that Mesocyon sometimes placed its heel on the ground rather than walking entirely on its toes as dogs do today.

University of Michigan paleontologist Anne Kort identified a fossil as one of the most complete Mesocyon coryphaeus specimens found yet. Kort said the dog, which was about the size of a coyote, likely at least occasionally walked from heel to toe and was not adapted for running, whereas modern dogs walk on their tip toes and are adapted for running. 

Credit: Anne Kort, University of Michigan



Extinction erased a different dog ecology

Kort says the specimen also illustrates a broader consequence of extinction. When a species and its relatives disappear, the distinctive way they lived disappears with them.

“This fossil is not our current dogs’ great-great-great uncle, because this whole line went fully extinct. And with that extinction, we did lose a whole kind of dog ecology that we just don’t see anymore,” she said. “I think sometimes there’s an assumption that life finds a way if something goes extinct. It will be replaced, or something will magically bounce back.

“But evolution never finds a perfect fit, it finds good fits. So when we lose things, they’re gone forever. They’re never going to be perfectly replaced, and I think that’s an important lesson to take away when we’re thinking about extinctions today.”

JODA paleontologist Ted Fremd originally found the fossil, made its recovery a priority, and completed the first preparation work that exposed the skull. JODA paleontologist Joshua Samuels assigned Cavin to remove the remaining skeleton from its protective jacket in 2011. Nicholas Famoso, now the chief paleontologist at JODA, later proposed that Kort study the specimen. Xiaoming Wang of the Natural History Museum of Los Angeles County is also a coauthor of the research.

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Wild Boars in Brazil Are Spreading Antibiotic-Resistant Bacteria, Scientists Warn

08 August 2026, By S. VARTAN

https://www.sciencealert.com/wild-boars-in-brazil-are-spreading-antibiotic-resistant-bacteria-scientists-warn

(Raimund Linke/The Image Bank/Getty Images)

If it feels like there are wild boars everywhere now, you're not imagining things.

Feral pig populations are rapidly expanding in North America (especially Texas and Arizona), Europe, and South America.

Now, besides causing damage to agricultural crops and invading suburban backyards, these wild boars could also be helping to spread antibiotic-resistant bacteria, according to a new study from Brazil.

Public-health officials in Brazil have been concerned that the commercialization of wild boars, which are being bred for food there, may harbor zoonotic and antimicrobial-resistant bacteria.

But they didn't have good data, just a strong hunch.

So to find out if their suspicions were true, researchers collected rectal swabs from 100 healthy European wild boars (Sus scrofa scrofa) raised on two commercial farms in Goiás State, Brazil.

A wild boar (Sus scrofa) in the Lainzer Tiergarten nature reserve in the southwest of Vienna, Austria.

 (Valentin Panzirsch/Wikimedia Commons/CC BY-SA 3.0 AT)



They screened the samples for Salmonella and E. coli, tested the bacteria against a panel of commonly used antibiotics, and searched for genes linked to virulence – the traits that can make bacteria better at infecting hosts.

The good news is that the researchers found very little evidence of Salmonella, but the bad news is that more than half of the animals carried E. coli, and almost every one of those bacterial strains was resistant to multiple antibiotics.

Although the one sample of Salmonella that turned up was resistant to several antibiotics, it lacked the virulence and resistance genes the researchers examined, suggesting the immediate Salmonella risk was relatively low.

E. coli painted a much more concerning picture.

The bacterium was isolated from 56 of the 100 wild boars, and 55 of them – a whopping 98.2 percent – qualified as multidrug resistant, meaning they could withstand antibiotics from multiple drug classes.

Resistance was particularly common against sulfonamides, tetracycline, amoxicillin, ampicillin, and doxycycline. If you recognize some of those names, it's because they are the most common, inexpensive frontline antibiotics.

A baby wild boar (Sus scrofa) in a wildlife park in the Netherlands.

 (Sander van der Wel/Wikimedia Commons/CC BY-SA 2.0)



Nearly all of the isolates remained susceptible to ceftriaxone, a critically important antibiotic in human medicine, but the researchers caution that even the small amount of resistance they detected deserves close monitoring.

Overall, they called the prevalence of drug-resistant E.Coli a "striking finding", which is as close to a 'yikes' as you can get from a scientist.

The team also looked for genes associated with bacterial virulence. Nearly 30 percent of the E. coli isolates carried the tsh gene, while fewer possessed papC and iss – genes linked to adhesion, survival in the bloodstream, and successful colonization of hosts.

Several bacteria carried more than one of these genes – combinations that could potentially increase their ability to cause disease.

According to farm managers, the wild boars were not routinely given antibiotics. That raises an obvious question: where did all this resistance come from?

The researchers suspect the environment itself may be the answer.

Antibiotic resistance genes can persist in soil and water, circulate among environmental microbes, and move between bacteria via mobile pieces of DNA.

Wild boars are also highly mobile, opportunistic animals that frequently interact with livestock, wildlife, and human-modified landscapes, creating all kinds of opportunities for resistant bacteria to spread even without direct antibiotic use.

Thinking holistically about the environment surrounding animals, even those in agricultural settings, is part of Brazil's One Health approach, which recognizes the "intersectoral health challenges" of human, animal, and environmental health.

Rather than viewing antibiotic resistance as purely a medical problem, One Health considers how resistant bacteria can move across ecosystems – from farms to forests, wildlife to livestock, and ultimately to people.

This systems thinking is why the researchers are looking at these wild boar-antibiotics issues.

https://www.youtube.com/watch?v=cUKIyXc37Ug

As commercial wild boar farming expands in Brazil and escaped animals continue to establish wild populations, these invasive pigs could become an increasingly important reservoir for antimicrobial-resistant bacteria.

The researchers argue that captive wild boars should now be considered part of the health-surveillance network.

European wild boars weren't always part of South America's landscape.

Domestic pigs arrived with European settlers centuries ago, while wild boars were introduced in the early 1900s by an Argentine rancher for hunting. Since then, escaped animals have spread across the continent, interbred with domestic pigs, and established thriving populations.

In Brazil, their success has been fueled by a landscape that offers the best of both worlds: forest fragments that provide shelter alongside agricultural fields full of calorie-rich crops like corn and sugarcane.

Their continued spread has turned them into one of the country's most successful – and controversial – invasive mammals.

The study does come with important caveats. The samples were collected between 2014 and 2017, so the scale of the issue may have changed in the years since.

The researchers also relied on farm managers' reports that antibiotics were not routinely used, rather than independently verifying those records, and they examined animals from only two farms.

Even so, the work provides some of the first detailed data on antibiotic resistance in wild boars in Brazil – and a timely reminder that the fight against antimicrobial resistance won't be won in hospitals alone.

Sometimes it starts by paying attention to what's wandering through the woods.

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This Ancient Grain Could Help Transform Children’s Gut Health

By Cornell U., August 7, 2026

https://scitechdaily.com/this-ancient-grain-could-help-transform-childrens-gut-health/

A biofortified pearl millet containing substantially more iron and zinc produced measurable changes in toddlers’ developing gut microbiomes.

 Credit: Shutterstock

Iron-rich pearl millet may improve toddler nutrition without disrupting the developing gut microbiome.

Each day, hundreds of toddlers in Mumbai’s urban slums ate porridge, soft curry, or freshly baked foods prepared for young children. Some meals contained ordinary pearl millet, an ancient grain widely eaten in India. Others used a specially bred millet with almost three times as much iron and more zinc than conventional grain. The foods tasted much the same, but the fortified grain was producing measurable changes inside the children’s developing gut microbiomes.

Iron deficiency is the world’s most common nutritional disorder, affecting about one quarter of the global population. Without enough iron, the body cannot make sufficient hemoglobin, the protein that carries oxygen in the blood. The resulting iron-deficiency anemia can interfere with physical health, brain development, and cognitive function.

Researchers at the Cornell Joan Klein Jacobs Center for Precision Nutrition and Health, working with collaborators in India and at the University of California San Diego, studied toddlers who ate iron- and zinc-biofortified pearl millet for nine months. They found none of the adverse effects commonly associated with higher iron intake. Instead, the children developed distinct gut microbial changes that may be beneficial.

Published in Nature Communications and presented at the American Society for Nutrition’s annual meeting, the research is believed to be among the first studies to examine how eating a biofortified crop affects the human gut microbiome.

“We thought that a food-based approach could help us move away from one-size-fits-all supplementation strategies to address population health, while also being a way to personalize nutritional interventions,” said Dr. Saurabh Mehta, founding director and Janet and Gordon Lankton Professor at the Jacobs center in the College of Human Ecology, and the principal investigator on the study. “So, we decided to test it.”

Iron deficiency affects approximately one in four people and can be especially damaging during early childhood, when it may slow brain development and weaken resistance to infection. Iron supplements can correct the deficiency, but previous research has identified an important drawback. Because the body absorbs only part of a large supplemental dose, excess iron can reach the colon, encourage harmful pathogens, and restrict beneficial microbes. Supplements may also cause diarrhea, constipation, and tarry stools. Those effects are particularly concerning in infants and toddlers because their gut ecosystems are still developing and remain highly sensitive to outside influences.
A staple crop tests a safer approach

The trial included 223 children between 12 and 18 months old living in Mumbai’s urban slums, where iron deficiency and anemia remain widespread. Half received meals prepared with biofortified millet containing 8.7 mg of iron per 100 grams. The remaining children ate standard millet containing 3 mg per 100 grams. Researchers collected rectal swabs before and after the intervention, then sequenced the samples to chart each child’s gut microbial community.

“We had to work with growers to develop the millet. Then we procured 38 tons of millet, split between the two types, and we had to identify storage facilities with the proper temperature and humidity,” said Samantha Huey, research associate in the Jacobs center and co-first author of the study. “We tested it for contamination and to make sure it had the iron and zinc we wanted it to have.”

SNDT Women’s University in India helped create the millet recipes and foods. Working with the Mumbai-based Centre for the Study of Social Change, researchers distributed the meals across 20 locations. At every feeding center, a research assistant recorded how much each child consumed twice daily, with another meal sent home. The schedule continued six days per week for nine months.

Microbial genes reveal what changed

“The sequencing technique that was used allowed us to delve deeper than just describing the types of bacteria present in these children’s guts – we could also understand what they were actually doing,” said co-first author Nathanial Cole, a postdoctoral associate in the Jacobs Center.

“We compared the DNA from these children’s gut communities to reference DNA from other species with known functions, allowing us to predict what these microbes were doing based on genetic similarities,” he said. “This approach enabled us to track how the gut microbiome developed over time and how it responded to the biofortified pearl millet.”

The biofortified millet was associated with increased activity in microbial pathways involved in resisting pathogens. These included pathways that produce natural antibiotic-like compounds, along with antioxidant metabolism that helps support a healthier intestinal environment. By the end of the trial, the children who received the fortified grain also had fewer microbial markers associated with harmful bacteria.

The researchers observed another pattern in both groups. As the toddlers grew older, their gut microbiomes became more diverse and developed a broader range of metabolic abilities, making them better prepared to process different foods. This progression is expected as a healthy gut ecosystem matures during the first years of life.

Biofortification could scale beyond supplements

“Iron supplementation is usually given at high doses because it isn’t well absorbed, but excess ends up in the colon and can allow harmful bacteria to proliferate,” Huey said. “Biofortification increases the nutrient density of the plant via genetic engineering, agronomic practices or – what we used – traditional cross breeding.”

Supplements depend on reliable distribution systems and consistent individual use. Biofortified crops could instead be cultivated, prepared and eaten in the same ways as ordinary staple foods. That could make them a more self-sustaining strategy, Huey said.

Larger studies involving more diverse populations will be necessary before biofortified crops can be recommended as a gut-friendly alternative to supplements. Even so, the approach may have value in lower and middle-income countries as well as wealthier nations. Iron deficiency remains a significant problem in the United States, where biofortification could strengthen agriculture while providing climate-smart, high-yield staple crops with nutrients the body can readily absorb.

The strategy also reflects a broader shift in nutrition guidance toward minimally processed foods.

“The latest dietary guidelines are now stressing eating whole foods and limiting ultra-processed foods and additives,” Huey said. “Growing crops that are naturally more nutrient-dense, rather than relying on adding micronutrients back in during food manufacturing, aligns with these recommendations.”

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'Barbarians' Have Been Misunderstood For Centuries, Researchers Explain

06 August 2026, By D. NIELD

https://www.sciencealert.com/historys-barbarians-were-far-more-sophisticated-than-we-give-them-credit-for

(Lorado/E+/Getty Images)

The word 'barbarian' comes to use from the ancient Greeks: Originally meaning simply 'foreigner', its connotations quickly drifted towards savagery, wildness, and violence.

Those historical associations linger: These days, the term is most commonly used to suggest people who are primitive and aggressive.

In a study published in the Journal of Archaeological Research, a team of researchers from the US and Sweden breaks down how those labeled as barbarians throughout history aren't quite as disorganized and unsophisticated as narratives might have us believe.

The history, after all, was most often written by those under attack from these so-called barbarians, rather than the 'barbarians' themselves.

The Haudenosaunee were one of the groups studied, shown here fighting the Algonquian near Lake Champlain in the US 

(Wikimedia Commons/Public domain)

Four case studies are used to advance the authors' argument: the Vikings who raided fleets over centuries; the Haudenosaunee (Iroquois) Confederacy in North America, which reached its peak around 1700; the Sea Peoples of the Mediterranean; and the Comanche tribe of the American Southwest (most active in the 17th and 18th centuries).

"Historical knowledge about these groups comes largely from colonial or imperialist outsiders who mischaracterized them as irrational and violent," anthropologist Jennifer Birch of the University of Georgia and colleagues write in their published paper.

"This characterization masks the fact that these decentralized groups achieved large-scale strategic coordination in the absence of centralized power."

Digging into historical records and past studies, the researchers built up a framework that draws together commonalities between these various groups.

For example, decentralization was used as a deliberate strategy, making these groups – without a single leader or capital city – much harder to defeat.

The Comanche Meeting the Dragoons oil-on-canvas painting by US artist George Caitlin.

 (Wikimedia/Public domain)



Rather than looking to top-down leadership, these 'barbarians' relied on social ties with other clans and tributes, as well as trading partners, to further their interests.

The process of raiding was more strategic and less haphazard than it has been portrayed as well: The researchers acknowledge these activities as coordinated ways of amassing wealth, resources, and prisoners for the overall benefit of these groups.

"We propose that the decentralized, militarized nature of so-called 'barbarians' were conscious political strategies, often undertaken in opposition to encroachment on the part of pre-modern states and empires," write the study authors.

These strategies could be modified over time, the researchers point out, as the contemporary context changed. Resources could still be amassed, but the distribution was different.

However, this wouldn't necessarily have been evident to the Greeks, Romans, and other communities who encountered 'barbarians'. What outsiders described as uncoordinated was actually a careful mix of autonomy among groups and the pursuit of collective gains.

"This was accomplished by drawing down upon and augmenting a repertoire of institutions, resources, and strategies that allowed them to scale up their activities without the development of centralized power structures," write the researchers.

"The successful strategies of these groups involved balancing the actions and roles of multiple sets of institutions – clans, nations, and confederacies; kin groups, fleets, and nascent polities – in coordinated socio-political structures."

This helps reframe the historical narrative of how warfare and politics evolved in the past. It's also a reminder that history has largely been told by civilizations that wrote things down, yet that one-sided perspective rarely captures the full picture or nuances of different communities.

All of these groups were forced to adapt as more centralized powers with greater numbers took over the regions they lived in.

However, there's still a lot that we can learn from them – and the team is keen to see their framework applied to other groups too.

"Additional systematic cross-cultural comparison would offer much to the discussion of how large-scale decentralized collective societies functioned as well as identifying and explaining variation and change in the same," write the researchers.

We know that many cultures shared oral histories – and continue to do so to this day – histories that enrich the archaeological record, or even challenge what scientists and historians have drawn from it.

"Archaeological data alone may not be sufficient for observing and documenting the kinds of collective behaviors – e.g., alliances, strategic compacts, and military campaigns – that such groups engaged in," the researchers conclude.

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Two Mysterious ‘Ghost’ Ancestors Are Hiding in Our DNA

By R. Sanders, U. of California Berkeley, August 6, 2026

https://scitechdaily.com/two-mysterious-ghost-ancestors-are-hiding-in-our-dna/

A new genomic technique has revealed ghost ancestry from two unknown human lineages hidden in modern DNA. 

Credit: SciTechDaily.com



Neanderthals and Denisovans interbred with the ancestors of modern humans, leaving recognizable traces in our DNA. Evidence now suggests that modern humans also interbred with two much older, unidentified ancestral groups.

Hidden within the genomes of people alive today are fragments of DNA from two unidentified human ancestors. Researchers at UC Berkeley traced these genetic regions to ancient episodes of interbreeding involving modern humans and at least four archaic human groups.

Earlier studies had suggested that modern humans mixed with hominins beyond the now-extinct Neanderthals and Denisovans. The new analysis goes further by locating the DNA inherited from these unknown populations and estimating when the interbreeding occurred. To uncover those relationships, the researchers developed a method that reconstructs ancient genealogies from hundreds of present-day human genomes.

Using genealogical relationships in DNA, TRACE uncovers hidden contributions from extinct human populations that left no sequenced genomes. 

Credit: Meaghan Marohn

Two unknown lineages entered our DNA

One unidentified population, described as a ghost ancestor, interbred with modern humans in Africa before 50,000 years ago. This happened before the most recent migration of Homo sapiens from Africa into Europe and Asia.

DNA from this lineage accounts for around 1% of the modern human genome, roughly comparable to the amount inherited from Neanderthals. The ghost lineage separated from the ancestors of modern humans around 800,000 years ago, near the time when Neanderthals and Denisovans diverged, although its interbreeding with modern humans occurred earlier.

“Previous publications suggested that there might be ghost ancestry — ancestry from unknown archaic lineages in modern humans — but they hadn’t concluded whether this unknown ancestry is present only in Africans or not, and when this introgression event happened,” said Berkeley graduate student Yulin Zhang, one of two first authors of the study. “We were actually able to find and map genomic locations in modern humans that are from this ghost lineage and show that this ghost ancestry is in all modern humans, not only in Africans.”

A timeline showing four separate instances (colored arrows) of archaic hominins interbreeding with early Homo sapiens. The dates were inferred from a genealogical analysis of present-day human genomes using TRACE, a technique developed at UC Berkeley.

 Credit: Yulin Zhang and Priya Moorjani/UC Berkeley

The second unidentified population, called a super-archaic ancestor, belonged to a hominin lineage dating back 1.8 million years. It interbred with Denisovans in Eurasia, and Denisovans later passed some of that super-archaic DNA to modern humans through interbreeding with Homo sapiens.

“The super-archaic finding is particularly exciting because it reveals genetic contributions from a human lineage that lived over a million years ago, despite the absence of any sequenced DNA from that population,” said Arjun Biddanda, a postdoctoral researcher at Johns Hopkins University and a co-first author of the study

The results reinforce a growing view of human evolution in which early modern humans repeatedly encountered related hominin populations across Africa and Eurasia. These groups were genetically similar enough to produce offspring together throughout much of the past million years.

“With ancient DNA from Neanderthals and Denisovans and with these new genealogical methods, we are learning that mixture among human populations has been very pervasive across time, and that this is also likely to be true at ancient time scales,” said Priya Moorjani, a Berkeley associate professor of molecular and cell biology. “We often think of human evolution as a branching tree, but new genomic data and analytical methods reveal a much more interconnected history — more like a complex web of populations connected by repeated episodes of migration and mixing.”

The identities of the ghost and super-archaic ancestors remain uncertain. However, their estimated divergence dates overlap with Middle Pleistocene Homo groups living in Africa about 800,000 years ago and Homo erectus populations in Eurasia around 1.8 million years ago.

Zhang, Biddanda, Moorjani and their colleagues published their findings July 30 in the journal Science.
Known fossils revealed only part

Modern humans leaving Africa approximately 50,000 years ago encountered and interbred with Neanderthals and Denisovans in Eurasia. Both older lineages eventually disappeared, but parts of their genomes survived in their modern human descendants.

Researchers uncovered that history by extracting and sequencing ancient DNA preserved in Neanderthal and Denisovan fossils. Yet the human genome also contained signs of interbreeding that appeared to be much older.

Identifying the source of those signals was difficult because no DNA has been recovered from the other extinct hominins that might have contributed them.

TRACE reconstructs ancestry without fossils

Moorjani’s group created TRACE (TRacking Archaic Contributions via ARG Estimation), a method that searches for archaic DNA using complete genomes from living people rather than genetic material from ancient fossils.

The researchers analyzed genomes from populations around the world and reconstructed an ancestral recombination graph (ARG), which charts how segments of DNA connect through shared ancestry across time.

“Genealogies preserve a record of our evolutionary past,” said Moorjani. “TRACE reconstructs those histories across the genome. By identifying regions whose ancestry extends unusually far back in time, we can uncover genetic contributions from extinct human populations, even in the absence of ancient DNA.”

As an initial test, TRACE identified some exceptionally old regions that matched the sequenced Neanderthal genome. Neanderthal ancestry accounts for about 1% of the modern human genome.

When the researchers focused on people from Asia and Oceania, the populations with substantial amounts of Denisovan ancestry, the method also correctly located known regions of Denisovan introgression.

Many other ancient DNA segments matched neither Neanderthals nor Denisovans. The researchers concluded that these regions came from two separate lineages that entered the human family at different times.

Ghost ancestry appeared in both African and non-African populations. That widespread distribution indicates that the interbreeding occurred before modern humans made their final major departure from Africa and expanded around the world.

“We discovered that about 2% of the modern human genome is from archaic hominins,” Zhang said. “In the case of the ghost lineage, modern-day Africans and non-African populations both inherited similar amounts of ghost ancestry. Each individual has about 0.5 to 1% of their genome inherited from this ghost lineage.”

To recover evidence of the second lineage, the researchers examined genomes from people in Oceania, where Denisovan ancestry can reach as much as 4%.

The super-archaic signal appeared inside regions inherited from Denisovans, suggesting that Denisovans first acquired this DNA and later passed it to modern humans. Denisovan genomes contain between 3% and 5% super-archaic ancestry, but only a small portion of that DNA reached people living today, Moorjani said.

“TRACE allowed us to contextualize how the ancestry segments from these previously uncharacterized hominins are distributed throughout the human genome,” Biddanda said. “We found that these contributions are widespread throughout the genome, and ghost ancestry is detected even in regions previously thought to be intolerant of Neanderthal and Denisovan ancestry.”

Ancient mixing may shape immunity

Moorjani said many of the inherited archaic segments are concentrated in genomic regions associated with immune and metabolic functions.

“This pattern is not entirely surprising,” she said. “Adaptation to new pathogens and food sources has been one of the strongest selective pressures in human evolution. Interbreeding with other human groups introduced new genetic variation, providing additional raw material for natural selection. Beneficial variants could then be retained and spread over many generations.”

As global genome databases become more representative of human diversity, Moorjani hopes TRACE will uncover weaker signals from still more unknown lineages.

Additional Denisovan genomes would also improve the analysis, since only one has been published. Recently sequenced proteins from Homo erectus fossils may even help researchers determine the identity of the super-archaic ancestor.

“I think these new computational methods that allow us to reconstruct genealogical relationships are really the next frontier in this field because they are allowing us to uncover hidden episodes from our past without requiring ancient DNA,” she added.

Moorjani noted that TRACE should also work with other species, “allowing us to also uncover really different patterns across the tree of life.”

The birth of modern Man

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How Brown Tree Snakes Became an Unstoppable Invasive Species

BY T. DINKI, U. AT BUFFALO, JULY 28, 2026

https://scitechdaily.com/how-brown-tree-snakes-became-an-unstoppable-invasive-species/

Brown tree snakes are an invasive species in Guam.

 Credit: Bjorn Lardner, United States Geological Survey

Biologists have long wondered how such a small number of individuals from the invasive species managed to colonize the island so successfully.

Few invasive animals have reshaped an ecosystem as dramatically as the brown tree snake, a species commonly used in textbooks to illustrate the damage biological invasions can cause.

Native to Australia and the South Pacific, the snake reached Guam sometime after World War II, possibly as a stowaway on cargo aircraft. It has since eliminated many native forest birds from parts of the island and causes hundreds of electrical outages each year by climbing utility poles. In some areas of the U.S. territory, populations reach as many as 30,000 snakes per square mile.

That extraordinary expansion has long puzzled biologists. Guam’s population apparently began with only a small number of snakes, so extensive inbreeding should have reduced their capacity to adapt and limited their growth.

Hidden DNA changes may explain success

The snakes may carry far more genetic variation than earlier methods could detect, according to a University at Buffalo-led study published on July 24, 2026, in Science Advances.

Researchers from UB and the U.S. Geological Survey (USGS) used advanced long-read sequencing to examine large sections of the brown tree snake genome. They uncovered thousands of structural variants, including duplicated, deleted, and rearranged stretches of DNA, many of them concentrated in genes connected to immunity and smell.

This overlooked variation may help explain how a population established by only a few individuals survived a severe genetic bottleneck and became so successful.

Brown tree snakes are skilled climbers and mostly active at night.

 Credit: USGS



“The brown tree snake is maybe not wildly diverse, but it has important sources of genetic diversity that have been underappreciated,” says the study’s corresponding author, Trevor Krabbenhoft, PhD, associate professor in the UB Department of Biological Sciences.

For agencies that have spent decades attempting to contain the snakes on Guam, the results may be discouraging. For conservation biologists, however, they suggest that endangered and inbred populations could retain more capacity to adapt than previously recognized.

“It’s possible that endangered species may have more flexibility in their genes than we realize,” says first author Christopher Osborne, PhD, a former PhD student in Krabbenhoft’s lab and now an aquatic biologist with State University of New York Oswego. “We’re now getting a better understanding of unappreciated sources of genetic diversity that may explain how some inbred species can still respond to their environment.”

Long reads expose missing variation

Traditional assessments of genetic diversity often focus on differences in individual DNA letters, such as changing an A to a G or a T to a C. Early sequencing technologies largely restricted researchers to finding these single-base-pair differences.

Long-read sequencing can examine much larger sections of DNA and detect structural variants affecting at least 50 base pairs at a time. Across the genome, these large changes involve nearly eight times more DNA than single base-pair variations.

“It’s like looking at portions of two books letter by letter with a magnifying glass and thinking they’re the same, but not realizing entire paragraphs have been moved around or duplicated. Older sequencing technology didn’t allow us to easily see that DNA in one individual might be in a completely different place on the chromosome than in another,” says Levi Gray, PhD, a postdoctoral researcher in Krabbenhoft’s lab. “How we define genetic diversity and how we actually measure it is shaped largely by the technology of the day.”

Gray had previously investigated Guam’s brown tree snake problem while working with the USGS. That connection gave the researchers access to DNA provided by the USGS Brown Treesnake Rapid Response Team (RRT), which works to prevent the species from spreading elsewhere in the U.S. and its territories.

Immunity and smell genes stand out

Analysis in Krabbenhoft’s laboratory identified more than 19,000 structural variants in the brown tree snake genome. Each marks a location where stretches of DNA differ through duplication, deletion, or rearrangement.

The variants were not spread evenly throughout the genome. Instead, they appeared especially often in genes related to immune function and olfaction, the sense of smell.

Brown tree snakes depend heavily on smell to find food, using their forked tongues to collect chemical signals from the air. The unusual diversity in their olfactory genes may help explain a behavioral difference between populations. In their native range, the snakes sometimes eat other snakes, but there is little evidence of this behavior on Guam.

“The snakes’ heightened sense of smell may allow them to recognize one another as something more like siblings — especially given the high levels of inbreeding — than as prey,” Gray says.

The variants’ origins remain unknown

Researchers still do not know whether these structural variants existed before brown tree snakes reached Guam or developed afterward. Large-scale genomic changes usually build up across many generations, although some research suggests that severe population bottlenecks can speed their formation.

“Is it possible some of this diversity emerged after the invasion? It is, but we would have to sequence snakes from the native populations to know for sure,” Gray says.

The Life of Earth

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Feeling a Presence, Seeing Visions, Déjà Vu? Huge Study Maps The 'Uncanny' Experiences We Rarely Talk About

06 August 2026, By M. IRVING

https://www.sciencealert.com/ever-experienced-something-you-cant-explain-detailed-study-investigates-how-people-deal-with-the-uncanny

(David Wall/Moment/Getty Images)

Have you ever heard a voice when you were completely alone? Or felt the presence of some unseen being?

You're not alone; around 60 percent of Americans believe they've had some kind of unexplainable experience.

But was it scary? Inspiring? Perhaps it invoked a new spirituality in you, or made you feel closer to a deceased loved one.

Or maybe it just sent you to the doctor for a brain scan.

Whatever happened, and however you responded to it, there isn't much research into how humans process weird events.

So, social psychologists at the D'Or Institute for Research and Education (IDOR) in Brazil set out to investigate just that, for a new paper published in PLOS One.

The team built on a previously developed questionnaire called the Inventory of Nonordinary Experiences (INOE), which asks participants whether they've ever experienced any of 38 spooky happenings and, if so, the context and aftermath of the event.

The researchers then gave their new 47-question quiz to 5,117 people in Brazil before conducting statistical analyses of the results.

The outcomes are as intriguing as you'd expect.

Out-of-body experiences were one of the 'nonordinary experiences' in the questionnaire. 

(sdominick/E+/Getty Images)



"Experiences like sensing a presence, having a vision, or feeling as though you are observing yourself from outside your own body are far more common in the general population than clinical diagnosis rates would suggest," says senior author Ronald Fischer, a psychologist at IDOR.

"We observed that most people in our sample of over 5,000 participants who report them are not unwell, and most describe them as neutral or positive – both at the time they occur and also when looking back and reflecting on that experience."

Things that constituted a 'nonordinary' event included sudden, overwhelming feelings like joy, awe, or fear; seeing visions; hearing voices; out-of-body experiences; a sense of diminished self; feeling the presence of the deceased or extraordinary forces; deja vu; extrasensory perception; near-death experiences; lucid dreams; or a sense of having lived past lives.

If participants responded that they had experienced any of these, they were then asked a few questions about the context of their experience. That included their mental state – such as whether they were awake and alert, dreaming, just falling asleep or waking up, or under the influence of drugs or alcohol – and where they were at the time.

The participants also had to answer how long the experience lasted, how often it happened to them, and the rough age they were when it occurred or started.

Next, they were asked who or what they felt was responsible, such as gods, angels, demons, spirits, or other entities; and why they might have been 'chosen' for the experience.

Many people reported feeling a 'presence'. 

(Catherine McQueen/Moment/Getty Images)



Finally, the participants were asked whether the experience had helped or hindered what they were doing at the time, how pleasant or uncomfortable the experience was, and what impact it had on their life afterward.

The results were intriguing.

More than 60 percent reported having their experiences while awake and alert, and almost 40 percent were alone at the time. About 36 percent said their experience lasted a few minutes, while 27 percent said it was very quick or almost instantaneous.

Roughly 19 percent couldn't keep track of time during the event.

The most common number of occurrences for a single person was, surprisingly, two to three times, with 38 percent of the respondents. Another 30 percent said the experience had happened just once.

Two-thirds said the experience occurred or began when they were adults, while more than 20 percent reported something strange during their adolescence.

Interestingly, when asked who they believed was responsible for their experience, 36 percent reported that they didn't believe that anyone caused it. A god or gods was the next highest, at 16 percent, while 11 percent attributed it to some kind of holy spirit.

Following a similar pattern, when participants were asked why it happened, 41 percent attributed it to random chance, while 28 percent said it was a 'sign' or a message.

Participants were fairly evenly split on whether their experiences were something that science could or eventually would be able to explain. But the scales were tipped ever-so-slightly towards the answer that 'no, something else is involved.'

Almost half of participants said that they felt joy or well-being during their experience, while less than a quarter experienced suffering or discomfort.

About half also reported that they felt positive or very positive effects on their lives afterward, while less than 15 percent reported negative effects.

"For many people, such experiences can be meaningful and lead to personal growth and insight," says Fischer.

"Highlighting these possible positive outcomes is important to help people make sense of them and help to normalize them."

The researchers say that these kinds of experiences are largely unstudied academically. But regardless of what's actually going on, understanding them in more detail could help support people who report strange things.

"Importantly, we hope our work can help to remove stigma by focusing on the diverse ways that people experience and make sense of them," says Fischer.

"However, we would also stress that if people feel that these experiences interfere with their daily activities, then they should talk to a professional or seek help from somebody that they trust."

The Life of Earth

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'Only One Conclusion': Radical Study Suggests Life on Earth Arose Twice

06 August 2026, By M. Irving

https://www.sciencealert.com/radical-study-suggests-life-on-earth-arose-from-non-living-matter-twice

(witsawat sananrum/iStock/Getty Images Plus)

The fact that you, or I, or any living creature, is here at all is a series of astonishing strokes of luck stretching back more than 4 billion years.

One of the biggest hurdles was the very first one: How did life emerge from a primordial soup of stuff that very much wasn't alive?

A radical new study, published in Science Advances, suggests that this unlikely threshold may actually have been crossed not once, but twice.

Two of the main lineages of life – bacteria and archaea – may have independently figured out the secrets of metabolism that upgraded them from non-living to living, according to the new study, which focused on the most rudimentary set of chemical reactions thought to enable this transformation.

"The surprise is that the enzymes that catalyze those reactions are not conserved across the evolutionary divide that separates bacteria and archaea," says William Martin, a biologist at Heinrich Heine University Düsseldorf in Germany.

"The new data leave only one conclusion. The bacterial and archaeal lineages made the transition to the free-living state independently. Only free-living cells are alive.

"Let's call it by name: we are looking at one origin of the genetic code, but two origins of life."

That's a huge claim to make, especially when defining what life even is can be surprisingly tricky.

https://www.youtube.com/watch?v=nNK3u8uVG7o

Generally speaking, life is considered matter that responds to its environment, takes in energy, grows, and reproduces itself.

That sounds like it should cover the basics, but even that broad a statement is imperfect. After all, viruses can do most of those, but aren't traditionally considered 'alive'.

One aspect of life that is universal – and which viruses lack – is metabolism, the collection of chemical reactions that organisms use to make molecules that are vital for their everyday functioning.

Enzymes are the workhorse proteins that act as catalysts for these reactions in organisms, but that raises a weird chicken-and-egg question.

Enzymes themselves are products of chemical reactions – so how did the first lifeforms begin metabolizing things, including making enzymes, without the help of other enzymes?

The answer, it seems, lies in their surroundings.

It's generally believed that the first life arose in extremely reactive environments, such as hydrothermal vents. Metals that naturally occur in these places could have been the first catalysts for metabolism, converting compounds like hydrogen gas, ammonia, and carbon dioxide into other useful molecules.

"Almost everything about the origin of metabolism is debated, including the roles of energy, genetics, autocatalysis, phosphate, cofactors, cyanide, CO2, and water," Martin and colleagues write in their paper.

"Yet on one aspect all will agree: the ~400-reaction network that converts H2, CO2, NH3, H2S and phosphate into amino acids, bases and cofactors cannot have arisen in an instant.

"Its emergence from spontaneous environmental reactions had to traverse intermediate states of assembly, which have previously been elusive."

The researchers investigated the protein structures of core metabolic enzymes in the genomes of bacteria and archaea, and developed a method and algorithm to order them in complexity. From there, they could determine which ones evolved in which order, and put together a rough timeline.

Starting compounds are shown at the left; they are converted by metabolism into the building blocks of life. The 420 enzymatic reactions are indicated as circles, and chemical metabolites as diamonds; lines connect reactions that share metabolites. Circles shown in magenta shading indicate reactions that could have been catalyzed by inorganic compounds in the environment where metabolism of the first cells arose. 

(HHU/Nadja Hoffmann)



"We found that the last universal ancestor of all cells, LUCA, possessed enzymes for only about half of the reactions of metabolism," says Martin.

"The other half was catalyzed by metals in the environment where LUCA arose."

The team found that there were likely four different phases in the development of catalysis (enzyme-driven reactions). The first relied solely on metals in the environment.

Once enough of the useful molecules built up, the not-quite-living-yet proto-cells (which included LUCA) could start developing their own enzymes that performed some of the functions of those metal catalysts.

Over time, later proto-cells developed more and more enzymes, reducing their dependency on external metals, until they no longer needed them at all. Only at that point would they be considered 'free-living cells'.

Importantly, the researchers say, this didn't occur until after bacteria and archaea had separated. These two branches figured out their own ways to tackle the same problems.

"We can see cases where the ancestors of bacteria and archaea independently evolved structurally distinct enzymes to catalyze the same essential metabolic reaction," says Natalia Mrnjavac, a biologist at Heinrich Heine University Düsseldorf.

"Such parallel inventions could have paved the way to the independent emergence of free-living bacteria and archaea."

The study may also plug another gap in our understanding of the origins of life.

A molecule called ATP is now a vital energy source to fuel metabolism – but it's also made by enzymes, and wasn't available in prebiotic chemistry. The researchers say they identified an alternative.

"When we react phosphite, a form of phosphorus that naturally occurs in hydrothermal vents, with organic compounds, we get metabolic phosphorylation reactions overnight in water," says Manon Schlikker, a molecular evolutionary scientist at Heinrich Heine University Düsseldorf.

"Phosphite and palladium replace ATP and enzymes; it's amazing, and it makes early evolution a lot easier to grasp."

Yet critical to chemical reactions is the medium in which they occur, and scientists still don't have a clear idea about that. Was it water, or a sticky goo?

If the findings are backed up with further research, it seems that the tree of life, as we picture it, may need an update. We tend to think of LUCA as the 'trunk' of the tree, with all the other lifeforms, past and present, branching off from there.

But perhaps there were two completely separate trunks, which first diverged at the roots, before they were even technically alive.

The Life of Earth

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Drug-Resistant Bacteria May Be Jumping Between Pets And Humans, Scientists Warn

26 July 2026, By F. MacDonald

https://www.sciencealert.com/drug-resistant-superbugs-may-be-jumping-between-pets-and-humans-scientists-warn

(Clouds Hill Imaging Ltd./Getty Images)



In 2022, a batch of chicken and duck embryos that died before hatching arrived at a veterinary lab in China for testing.

Buried in their brain tissue, researchers found Acinetobacter baumannii – a pathogen labelled 'Priority 1′ by the World Health Organization'. It's best known for tearing through hospital ICUs due to its resistance to even last-resort antibiotics.

It's also more recently starting to become recognized as being zoonotic: capable of moving between animals and people.

It's long been thought that livestock may play a role in spreading drug resistance in superbugs.

But, interestingly, the specific strains of bacteria isolated from the poultry weren't actually resistant to much of anything.

https://www.youtube.com/watch?v=PcYOc-LxZzs

When comparing this genetic data to that found in humans and companion animals such as cats and dogs, the researchers from Nanjing Agricultural University, Wuhu Institute of Technology, and Nanjing University of Chinese Medicine in China found that the real concern turned up somewhere closer to home.

Researchers pulled together genetic data on 509 A. baumannii samples collected from animals in 17 countries, spanning 33 species – everything from white storks in Poland (which, oddly, make up a vast proportion of the animal samples on record) to cats, dogs, and horses in veterinary clinics across Europe.

Combined with thousands of human clinical samples from the same regions, plus the new poultry data, the picture that emerged wasn't reassuring for pet owners.

"A. baumannii isolated from animals can be divided into two groups: a high antimicrobial resistance (AMR) group dominated by hosts such as horses, cats, and dogs and a low AMR group dominated by hosts such as livestock, poultry, and wildlife," the researchers, led by Xiangkuan Zheng at Nanjing Agricultural University, wrote in the journal Applied and Environmental Microbiology.

(NickyLloyd/E+/Getty Images)



Using a classification system that groups related A. baumannii strains into "international clones" – the same lineages behind hospital outbreaks worldwide – the team found that several of these clones, including one called ST25, turned up again and again in companion animals.

ST25 alone was found in nine different animal species, mostly cats, dogs, and horses.

Bacteria from cats, dogs, and horses turned out to be genetically almost indistinguishable from strains infecting people in hospitals nearby, with genome similarity scores above 99 percent, and in some cases over 99.5 percent.

Livestock, poultry, and wild animals, by contrast, carried strains that were far more distant relatives – typically just 97 to 98 percent similar to the human strains.

"Our study suggests that A. baumannii has a higher potential of intertransmission between companion animals and humans compared to livestock, poultry, and wildlife," write the researchers. "This elevated potential may be related to the close contact of companion animals with humans."

Cats and dogs even carried resistance genes that livestock never should. Isolates from companion animals turned up two genes that make bacteria resistant to carbapenems – the antibiotics doctors reach for when nothing else works, and which are off-limits in livestock farming altogether. Those same resistance genes turned up in precisely zero of the livestock, poultry, or wildlife samples.

None of this means your dog or cat has given you a hospital infection, or ever will.

Let's be clear: there's no direct evidence here of the bacterium actually jumping from a specific pet to a specific person, just a genetic paper trail suggesting the opportunity is there, and has been for a while.

Last year, the American Society for Microbiology (AMR) published an article exploring the emerging link between antibiotic-resistant bacteria in pets and humans – which specifically flagged the need for more species specific pathogen sampling to help further understand the picture moving forward.

While this latest study gives us more important clues, there's still a long way to go.

What happens next is more sampling – of paws, feathers, hooves, and the humans standing next to them – to work out how often, and how easily, this hospital regular slips between species.

The Life of Earth

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