Scientists help verify Yucatan origin of cotton’s domestication

 Cotton is the world’s leading source of natural textile fiber, but much of its genetic history remains a mystery. Mississippi State scientists are part of an international team investigating when and where cotton was first domesticated. Their findings, recently published in the Proceedings of the National Academy of Sciences, weave together a clearer picture of cotton’s genomic past while offering insight to help improve the crop’s future.

Researchers sequenced nearly 400 wild and domestic cotton plants across Florida, the Caribbean and Mexico. They traced modern cotton’s roots to Mexico’s Yucatán Peninsula more than five millennia ago, uncovering genetic diversity that could help today’s breeders develop more resilient cotton.

Professor Dan Peterson, head of MSU’s Department of Biochemistry, Nutrition and Health Promotion and a Mississippi Agricultural and Forestry Experiment Station scientist, said the team confirmed a longstanding hypothesis that the Northwestern Yucatán Peninsula was the center of domestication of Gossypium hirsutum, known as upland cotton. Peterson noted wild specimens of the species hold valuable reservoirs of traits that could improve the crop today.

“When breeders select plants for desirable traits, they create highly specialized cotton varieties but also reduce genetic diversity,” he said. “As diversity declines, so does the plant’s ability to withstand new threats. Protective genes can be lost during breeding, leaving modern cotton vulnerable to emerging diseases. That’s why wild cotton populations are vital. Their rich genetic diversity continues to evolve under natural environmental pressures, providing valuable traits for future breeding efforts.”

Peterson said researchers have studied the origin of cotton’s domestication for more than 75 years. Early scientists noticed much of cotton’s diversity appeared to originate in the Yucatán, supported by closely related plant types and archaeological evidence of ancient people in the area using cotton.

“We’re confirming and building upon what earlier researchers discovered through years of painstaking work,” Peterson said.

Sequencing a genome, he said, is like solving a jigsaw puzzle.

“We can’t read a chromosome from end to end. We must sequence then reassemble many DNA pieces. In the past, those pieces were very short, making the process incredibly complex. Recent advances allow us to sequence much longer DNA stretches,” Peterson said. “It’s the difference between solving a 100-piece puzzle compared to one with a million pieces.”

Tony Arick, interim director of the MSU Institute for Genomics, Biocomputing and Biotechnology, said the modern process is easier and less expensive.

“The longer the DNA string, the better and easier it is to map. Using the jigsaw puzzle analogy, it’s much easier to see the big picture when there are fewer missing pieces,” he said.

Bigger bodies were a late addition for humans

 

The biggest jump in body size among our ancestors happened around 2 to 2.5 million years ago, with the appearance of Homo rudolfensis or Homo erectus/ergaster, rather than gradually across the whole human family tree. 

New research published today (Monday, 22 June 2026) in the journal PNAS, found that some species bucked the trend completely. Homo floresiensis and Homo naledi stayed small, with the early hominin Australopithecus weighing 40kg, on average, and reaching the height of a child. Other branches of Homo grew larger. Homo erectus/ergaster were the first hominins to weigh around 60 kg or more, on average, achieving weights similar to many modern humans.    

The University of Reading and University of Oxford findings challenge the idea that bodies simply got bigger and bigger over time in a steady line, eventually leading to modern humans. 

Dr Jacob Gardner, lead author at the University of Reading, said: "For years, different studies have come to different conclusions about whether our ancestors steadily grew bigger over time or jumped in size at some key point in our Homo ancestors. We think that's because everyone was looking at slightly different pieces of a much bigger puzzle. When you put all the fossils together, examine multiple competing ideas, and account for how species are related to each other, a clearer picture emerges. The answer is most likely a combination of these ideas. 

“The human story is not simply one of constant growth, but also of a major change that happened later, within our own genus, while other branches of the family, including some surprisingly small relatives, went their own way entirely." 

Piecing together the human puzzle 

Researchers reached these conclusions by looking at body weight from 386 fossils across 21 different species of hominins, the group that includes humans and our extinct relatives. They used statistical models to track how body size changed over millions of years. 

Previous studies disagreed because some focused on early relatives such as Australopithecus, others on later members of Homo, and some used different methods to estimate body weight from fossil bones. These studies also did not account for how hominin species were related to one another or the various uncertainties that come with an incomplete fossil record, such as which fossils belong to which species. Bringing all of this together in one model shows that these studies weren't actually disagreeing with each other, they were just looking at different parts of a more complicated story. Body weight steadily increased over time in our earlier hominin relatives, like Australopithecus, but then jumped in size at a key point later in Homo.  

The timing of this growth spurt lines up with other changes in later Homo. These ancestors were walking on two legs more efficiently than earlier hominins, eating more meat, and roaming over much larger areas in search of food and suitable habitat. A bigger body may have helped with all of these things, making it easier to travel long distances and survive on a varied diet. The findings suggest that growing larger was closely tied to a wider shift in how these early humans lived. 

Dr Thomas Puschel, co-author from the School of Anthropology and Museum Ethnography, University of Oxford, said: “Our results suggest that human body size evolution was not simply a story of steady growth over time. Although body mass generally increased throughout our evolutionary history, the most significant shift occurred later within the genus Homo. This change coincided with broader developments in how our ancestors moved across landscapes and exploited their environments, pointing to a close relationship between body size and major ecological and behavioural transitions."

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2521732123 

See the world of Stonehenge from your sofa

 

A new free online experience allowing anyone in the world to step inside the world of Stonehenge exhibition and explore thousands of years of history launches today (Sunday, 21 June). 

The Virtual World of Stonehenge, developed by researchers at the University of Reading and the British Museum, gives users an immersive digital tour of one of the most celebrated museum exhibitions in recent years. The original World of Stonehenge exhibition ran at the British Museum in 2022, attracting more than 190,000 visitors and bringing together over 400 objects from 36 institutions across Europe. 

Timed to release alongside the summer solstice, the new virtual version goes well beyond a simple recreation of the gallery. Users can go inside Stonehenge itself and watch it change through time, explore Neolithic flint mines at Grimes Graves, and discover rarely seen prehistoric objects through animation, soundscapes and interactive content. The experience is free to access via the British Museum website and works on desktop computers, tablets and phones. 

Professor Duncan Garrow, Professor of Archaeology at the University of Reading, said: "The original exhibition brought together an extraordinary collection of prehistoric objects, many of which had never been displayed together before. Now anyone, anywhere they are, can not only see those objects but understand the world of Stonehenge and experience how it looked and felt thousands of years ago. We hope it brings prehistoric Britain to life in a completely new way." 

Dr Neil Wilkin, at the British Museum, said: “This has been an amazing opportunity to think about the future of virtual museum exhibitions, not just at the British Museum but everywhere across the world”.  

Laser-scanning leaves, bracelets and crumbs 

The project was funded by UK Research and Innovation and builds on AHRC-funded research led by British Museum curator Dr Neil Wilkin, in partnership with Professor Duncan Garrow at the University of Reading. The team worked with the University of Southampton and digital heritage specialists ArtasMedia to transform a 3D laser scan of the original gallery, captured during the final weeks of the exhibition in 2022, into a fully interactive online experience. 

A particular focus of the project was making the stories behind lesser-known prehistoric objects more accessible. These include a 6,000-year-old elm leaf, a woven cow-hair bracelet, and the remains of a prehistoric feast, all of which are brought to life through new digital content developed specifically for the virtual exhibition. 

The launch coincides with the summer solstice, the moment when Stonehenge's alignment with the rising sun has drawn people to the site for thousands of years. 

The Virtual World of Stonehenge is free to access from Sunday 21 June: The World of Stonehenge: University of Reading and British Museum

Mystery of 17th century shipwreck holding 400 gold coins finally solved after 30 years

 The identity of a centuries-old shipwreck discovered off the south coast of England, holding 400 gold coins has finally been identified as the Dutch trading ship “Dom van Keulen” which left Morocco for the Netherlands in the autumn of 1633.

A new publication identifies the mysterious wreck that, for almost 30 years, a team of divers and researchers from the British Museum, Bournemouth University (BU) and the South West Maritime Archaeology Group have worked to identify. The book, called ‘From Morocco to the Coast of England: The Story of the Dom van Keulen and its Remarkable Cargo’ reveals that the Dutch ship came across some adverse weather.

Independent Historian, Ian Friel who helped identify the ship has uncovered documents in the National Archive relating to its voyage from Morocco to the Netherlands during which the crew “met with much tempestuous weather”. The ship sprang a leak and sank close to the coastal town of Salcombe, Devon off the south coast of England. All the crew survived.

Dave Parham, Professor of Maritime Archaeology at BU, who edited the book alongside Venetia Porter, former Senior Curator for Islamic and Contemporary Middle Eastern Art at the British Museum who worked with the South West Maritime Archaeology Group to find out more about the cargo and its ship after it was discovered in 1995.

Dave Parham said: “Among its cargo were 150 bags of gum arabic, 64 bags of saltpetre, 320 goat skins and 9,000 Barbary ducats, gold Moroccan coins. It is thought that most of the cargo was salvaged at the time, but more than 400 coins remained on the seabed until they were discovered by the South West Maritime Archaeology Group in 1995.”

Dave continued: “This provides important context for the wealth and architecture of the Sa‘dian Sharifs, the trade in African gold, and tangible evidence of the flourishing 17th-century maritime trade linking Morocco, the Low Countries and Britain.”

The 400 coins which along with other material from the wreck are on display at the British Museum originated from the Barbary Coast, recognised today as Morocco. During the 16th and 17th centuries, Dutch merchants actively traded by exchanging manufactured goods for highly valued, pure West African gold. At this time the Dutch had a large maritime industry and had a global trading empire. Many of the foreign imported ducats were melted down to produce their own Dutch gold coins which became one of the world’s most widely accepted trade currencies.

Very little is known about the appearance or size of the Dom van Keulen and no known paintings of the ship exist. Professor Parham says that the wreck site is about 30 metres long. It lies at a depth of around 18 metres and includes cannons and anchors amongst other small items of cargo. 

Other items brought up from the wreckage and now in the ownership of the British Museum include a pewter bowl and spoon, gold jewellery, a sounding weight in the shape of a fish, a stamp seal, pottery and a gold finger nugget.Head of Research at the British Museum, Jeremy D Hill, said:

“The discovery of African gold from under the sea off the coast of Devon was an amazing discovery that raised so many questions about how it came to be there. Answering those questions has taken a team of experts, working collaboratively. The story can now be told of how a Dutch ship carrying North African gold was wrecked off the English coast, making this a discovery of international importance. It reminds us how much there is still to be found under our seas.”

The book offers a detailed account of the find and the recovery process of the shipwreck. It also provides a cultural history of the Sa’dian Sharifs, an Arab Sharifian dynasty that ruled Morocco at the time the ship's crew would have been trading with them.

The wreck site is designated under the Protection of Wrecks Act 1973 and is closely managed by Historic England. Diving on the site is restricted to those that hold a licence granted by the Secretary of State at DCMS. The wreck is monitored by the National Coastwatch Institution (NCI) Prawle Point station, which overlooks the site. Devon & Cornwall Police’s marine unit also undertake regular patrols in the vicinity as part of Operation Birdie, a national initiative to tackle illegal interference with historic wreck sites.

An Open Access version of the book can be found online with physical copies available for purchase from the British Museum online shop.

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DOI

10.48582/eh04-q803 

Oldest strains of plague caused deadly outbreaks 5,500 years ago

 

Plague is commonly associated with rats, crowded medieval cities, and the epidemics that swept across Europe during and after the Middle Ages.

But a new study published in Nature shows that the disease was already lethal 5,500 years ago, where it killed humans in small, mobile hunter-gatherer communities – long before the rise of agriculture and cities created the conditions usually associated with plague epidemics.

An international group of researchers analysed ancient DNA from human remains found at four hunter-gatherer cemeteries in the Lake Baikal region of East Siberia. Using advanced DNA sequencing techniques, the researchers reconstructed ancient bacterial genomes preserved in teeth, revealing previously unknown early strains of plague.

“Whether the earliest forms of plague were mild or virulent has been a matter of debate, but our findings demonstrate that these ancient strains were already highly lethal,” says senior author Eske Willerslev, Professor at the University of Copenhagen and the University of Cambridge.

The study combines genetic, archaeological and radiocarbon evidence to reconstruct how the outbreaks unfolded within the prehistoric groups.

“Based on the plague DNA, the genetic relationships between the victims, the archaeological analysis and the radiocarbon dating, we’ve built a really clear, complete picture of what happened during these outbreaks,” says lead author Ruairidh Macleod, who carried out the work while a PhD student at the University of Cambridge – and is now Research Fellow at the University of Oxford.

In total, DNA from Yersinia pestis – the bacterium that causes plague – was detected in 18 of 46 individuals – nearly 40 percent. This is higher than the detection rate reported from some medieval plague pits.

More lethal than previously thought

Previous studies showed that early strains of Yersinia pestis lacked some of the genetic traits that later enabled bubonic plague to spread efficiently via fleas and rodent hosts. This led many researchers to believe that the earliest forms of plague were unlikely to have caused major outbreaks.

However, the new study challenges that assumption.

The mortality profiles at the two largest cemeteries show an exceptionally high number of children and young teenagers among the dead – something that had puzzled archaeologists working on the graves for decades.

“The unusually high number of children and the short timespan was a real puzzle that we’ve been trying to solve since the 1990s. Finding out that plague was the cause is extraordinary, but it makes so much sense,” says archaeologist Andrzej Weber of the University of Alberta, Principal Investigator of the Baikal Archaeology Project.

Radiocarbon dating showed that many of the burials occurred within a very short time span. In several cases, siblings or parents and children appear to have died and been buried together.

Did superantigen cause lethality?

The ancient plague strains also carried a unique superantigen – a toxin-producing genetic factor not seen in historic plague strains. Superantigens can trigger extreme immune responses and are associated with severe inflammatory complications, likely increasing the severity of infection.

“This finding changes our understanding of the earliest plague outbreaks: Even before the bacterium evolved efficient flea-borne transmission, these ancient strains appear to have carried a potent combination of virulence factors that could make infection highly lethal,” says senior author Martin Sikora, Associate Professor at the University of Copenhagen.

Together, the findings suggest that the earliest known plague outbreaks may already have been as deadly as later historical forms of the disease, especially for children, even without flea-borne transmission.

The study also supports the idea that plague may have originated in Central or North-East Asia before later spreading across Eurasia through wild rodent reservoirs. Archaeological evidence suggests these hunter-gatherers interacted closely with marmots – large burrowing rodents that still carry plague today – and researchers believe the outbreaks may have spread directly from infected marmots into humans.

Read the study “Lethal plague outbreaks in Lake Baikal hunter-gatherers 5,500 years ago”

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Journal

Nature

DOI

10.1038/s41586-026-10540-5 

Men in ancient Europe likely had better access to protein-rich foods than women did

A new Simon Fraser University study has found men in ancient Europe likely had better access to protein-rich foods than women did.

Analyzing samples from more than 12,000 skeletons from hundreds of sites across Europe over a 10,000-year period, researchers say the findings are strong evidence of long-suspected gender-based diet inequalities throughout history.

“We think these differences were largely culturally motivated,” says Michael Richards, archaeology professor and senior author of the study. “In earlier periods, animal protein was energetically ‘expensive’ to obtain, and in later periods it often carried higher monetary costs. As a result, it likely became a higher-status food and was preferentially consumed by males.”

Published in PNAS Nexus, the study analyzed isotopes found in 12,281 individuals across 393 sites in Europe dating as far back as10,000 years. Isotopes are chemical markers in human remains that allow researchers to reconstruct past diets. 

Nitrogen isotopes reflect the amount of animal protein consumed while carbon isotopes indicate how much plant-based foods, like grains, were ingested.

To compare inequality across different regions and time periods, researchers applied a method from economics known as the interdecile ratio. This approach provides a standardized way to measure how diets differed within populations.

Study results show men were more often among those with the richest diets, while women were more frequently among those with poorer diets. 

In early Neolithic farming societies (approximately 10000 to 2000 BC), diets were relatively similar, though differences between men and women were present. Inequality increased during the Bronze Age (3300 to 1200 BC), alongside advances in agriculture and more complex social hierarchies, and reached its peak in Classical Antiquity (700 BC to 500 AD).

Biological factors may account for some of the differences in diet, since females often (not always) require fewer calories per day than males, Richards says. But diet disparities widened over time, with the gap between the highest- and lowest-status individuals increasing based on nitrogen isotope values, explains Richards.

“This was especially pronounced in the medieval period, where clear dietary differences emerge between upper and lower classes of society,” he says.  

Co-authored by SFU postdoctoral fellow Rozenn Colleter, this research was conducted in collaboration with the National Institute for Preventive Archaeological Research and Géosciences Environment Toulouse. Some of the samples used in this study were analyzed in SFU’s Isotope Laboratory, one of the few isotope labs in the world based within a university archaeological department.

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Journal

PNAS Nexus

DOI

10.1093/pnasnexus/pgag033 

Rubbish heaps help reconstruct ancient Greenlanders’ farms, seal hunts, and toilets

 

Microbiome of ancient middens sheds new light on the daily life of Paleo-Inuit and old Norse

Peer-Reviewed Publication

Frontiers

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The authors during their fieldwork on Greenland

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Credit: Louise Hindborg Mortensen

Greenland has a long and checkered history of human settlement: several Paleo-Inuit cultures since approximately 2,500 BCE, descendants of Vikings between the tenth and fifteenth centuries, and early modern Danes since 1721. All left their traces on the landscape, for example in the form of ancient domestic rubbish heaps. Composed of waste like animal bones, excrement, mollusk shells, and human artefacts, these middens are a precious resource for archaeologists.

But what can microbiologists contribute to the study of these middens, for example revealing which diseases plagued historic populations, and which animals they kept but perhaps didn’t eat? And now that the Arctic is warming three to four times faster than the global average, could thawing middens be a source of resurgent infectious diseases?

“Here we show that the risk of release of ancient pathogens from ancient middens on Greenland is currently low,” said Dr Frank Møller Aarestrup, a professor at the National Food Institute of Denmark Technical University and corresponding author of the article in Frontiers in Microbiology. “Rather, we found that these middens in the cold Arctic acted like long-term natural experiments. Human- and animal-associated bacterial signals, including opportunistic bacteria and bacteria carrying antibiotic resistance genes, have remained detectable in them many centuries later as the legacy of human activity: for example, livestock farming by the ancient Norse.”

Studying the dustbins of history

In 2020 and 2021 in West and South Greenland, Aarestrup and colleagues collected samples from several middens frozen in time by permafrost and covering 4,500 years of human life in Greenland. These had been identified by the Greenland National Museum and Archives registry. At ancient Norse sites, for example at Kapisilit and Narsarsuaq, they also collected soil samples from historic winter enclosures and summer grazing grounds for livestock. The researchers used DNA sequencing to reconstruct entire bacterial communities. They compared their findings to those in 143 soil samples from areas of permafrost distant from any historical settlements.

The sequencing revealed between 9 and 202 bacterial species per midden, for a total of 1,207 species. Importantly, many of these species were previously undescribed and could only be assigned to broad taxonomic categories like families and orders. “This […] highlights how poorly described Arctic soils and archaeological deposits remain,” wrote the authors.

Middens had significantly richer bacterial communities than surrounding pristine soils, confirming that they preserved the biological legacy of human activity. Middens from the Paleo-Inuit had the most soil-like bacterial communities, indicating that the microbial imprint from humans and animals diminishes over time.

Groups of bacteria known to live on or within animal and human hosts predominated in most middens. These included harmless bacteria from human feces like Clostridium massilliamazoniense, Clostridium baratii which can cause botulism, and Paeniclostridium sordellii, which can cause life-threatening human diseases like toxic shock syndrome, sepsis, and gas gangrene.

Bacterial communities depended strongly on the type of waste material in each midden. For example, those from early colonial era Nuuk contained decomposing seal skins and were rich in the bacterium Clostridium perfringens, a major cause of food poisoning. Romboutsia species and Paraclostridium sordellii – which live in the gut of many animals – were abundant in middens filled with animal carcasses, while early Norse middens with decomposing bones were rich in unknown species of Proteobacteria and Clostridiaceae.

No reason to worry

The authors also found a great diversity of genes associated with antimicrobial resistance in bacterial genomes from middens. The presence of the same genes in ancient and contemporary soil layers signaled that microbes resistant to antimicrobials can linger in permafrost for centuries. However, the authors concluded from the spatial distribution of these pathogens that they don’t spread far from thawing middens. They thus appear to pose little risk to public health – at least for now.

"The microbiome in thawing permafrost appeared to be rapidly replaced by local contemporary environmental microbes once released into run-offs,” observed co-author Dr Saria Otani, an associate professor at the National Food Institute.

“However, it is not known whether the risk of release of pathogens will increase with increasing temperatures, or whether this might be greater in other Arctic regions. For this reason, it would be prudent to include microbiome characterization as a routine monitoring aspect during archaeological visits," counseled last author Dr Anders Priemé, a professor at the University of Copenhagen.

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Journal

Frontiers in Microbiology

DOI

10.3389/fmicb.2026.1809037