Two ancient populations that diverged later 'reconverged' in the Americas

A new genetic study of ancient individuals in the Americas and their contemporary descendants finds that two populations that diverged from one another 18,000 to 15,000 years ago remained apart for millennia before mixing again. This historic "reconvergence" occurred before or during their expansion to the southern continent.

The study, reported in the journal Science, challenges previous research suggesting that the first people in the Americas split into northern and southern branches, and that the southern branch alone gave rise to all ancient populations in Central and South America.

The study shows for the first time that, deep in their genetic history, many Indigenous people in the southern continent retain at least some DNA from the "northerners" who are the direct ancestors of many Native communities living today in the Canadian east.

"It was previously thought that Indigenous South Americans, and indeed most Native Americans, derived from one ancestry related to the Clovis people, who lived about 13,000 years ago," said Cambridge University archaeology professor Toomas Kivisild, who co-led the research with University of Illinois anthropology professor Ripan Malhi

"We now find that all Native populations in North, Central and South America also draw genetic ancestry from a northern branch most closely related to Indigenous peoples of eastern Canada," Kivisild said. "This cannot be explained by activity in the last few thousand years. It is something altogether more ancient." "We are starting to see that previous models of ancient populations were unrealistically simple," Malhi said.

The researchers analyzed 91 ancient genomes from sites in California and Canada, along with 45 mitochondrial genomes from present-day Native individuals. The work adds to the evidence that two populations diverged 18,000 to 15,000 years ago. This would have been during or after their migration across the now-submerged land bridge from Siberia along what is now coastal Alaska, the researchers report.

Ancient genomes from southwest Ontario show that after the split, Indigenous ancestors representing the northern branch migrated to the Great Lakes region. They may have followed the retreating glacial edges as the most recent ice age began to thaw, the researchers said.

Populations representing the southern branch likely continued down the Pacific coast, inhabiting islands along the way, the researchers found.

"The ancient Anzick child from Montana also represents the southern branch and is associated with the Clovis culture, which was once thought to be ancestral to all Native Americans," Malhi said. "The analysis of genomes from ancient peoples from Ontario and California allowed us to identify components of the northern and southern branches in contemporary Central and South American genomes. These components were likely the result of a 'reconvergence' of the two branches deep in time."

"The blending of lineages occurred either in North America, prior to the expansion south, or as people migrated deeper into the southern continent, most likely following the western coast," said Christiana Scheib, the first author of the study who conducted the work while at the University of Cambridge. "We don't have ancient DNA to corroborate how early this northern ancestral branch arrived."

Ancient tooth shows Mesolithic ancestors were fish and plant eaters

IMAGE: The Mesolithic tooth had evidence of fish scales and fish tissue. view more 

Credit: Sapienza University of Rome

Previous analysis of Mesolithic skeletal remains in this region has suggested a more varied Medittaranrrean diet consisting of terrestrial, freshwater and marine food resources, not too dissimilar to what modern humans eat today.
Although this recent find is the only example of a skeleton that provides evidence of both fish and plants in the diet of early people in this region, the researchers argue that the discovery provides a significant insight into the lifestyle of Adriatic and Mediterranean foragers.
The team found microfossils entombed in the dental calculus, commonly known as tooth plaque or tartar, of the young male skeleton, revealing fish scale fragments and fish muscle fibres.
Analysis also showed microfossils of plants in the dental calculus, which has not been identified in skeletal remains in this part of the Mediterranean before. The researchers point out that finding both ancient plant and fish deposits in the teeth further demonstrates the value of dental remains in the understanding of human evolution.
Dr Harry Robson, from the University of York's Department of Archaeology, said: "Whilst fishing during the Mesolithic period has been demonstrated by fish remains as well as fishing related technologies in the past, here, for the first time we have direct evidence that humans consumed these resources, or used their teeth for de-scaling activities, which is very unique.
"The skeleton, which has been dated to the late eighth millennium BC, is also significant in terms of its bone chemistry. Using carbon and nitrogen stable isotope analysis we were able to demonstrate that marine resources were a major component of the diet of this individual over a sustained period of time."
The team were unable to identify the fish scales, although they are thought to be very similar to tuna, mackeral, and gilthead sea bream.
Despite the lack of a grave, the male who was between 30 and 40 years-of-age, was probably purposefully buried there. Although long-term consumption of marine resources is a rare find for this period and region, dental analysis of more skeletal finds could help reveal if it was common to early human diets.
Lead researcher, Professor Emanuela Cristiani, from Sapienza University of Rome, said: "This is an exciting, but surprising finding. We only have three skeletal remains from this period that demonstrate the long-term consumption of marine-resources, so when you can identify microfossils of this kind, it can provide a great leap forward in our understanding.
"Our data provides a novel perspective on forager diet in the Mediterranean region by revealing the role of marine organisms during the Mesolithic.
"The recovery of starch granules from two wild grass groups in the dental calculus of the analysed individual, suggests that energy-rich plants were a part of the Holocene forager dietary habits in the region.

Genes from Icelanda's first settlers reveal the origin of their population

In just over 1,000 years, Icelanders have gone through numerous changes in their gene pool, to the extent that Iceland's first settlers, who came to the island from Norway and the British and Irish isles between the years 870 and 930, are much more similar to the inhabitants of their original home countries than to Iceland's present-day inhabitants.

This is one of the main conclusions of a study carried out by an international team of scientists which included members of the Spanish National Research Council (CSIC). For the first time, the researchers, whose results are published in the journal Science, analysed the ancient genomes of 25 individuals who lived in Iceland during the colonisation of the island.

With a population of 330,000, Iceland is a country with its own peculiarities. Genes are no exception: isolation and inbreeding throughout its history make this northern Atlantic island a paradise for genetic studies.

The analysis of ancient skeletal remains- more specifically the teeth belonging to the first generations to populate the island- has shed more light on the genetic evolution which led to a combination of genes coming from Scotland, Ireland and Scandinavia. According to the conclusions of this study, the Norwegian genetic fingerprint of present day Icelanders stands at 70%, while, in the case of the island's original founders, it was 57%.

As CSIC researcher Carles Lalueza-Fox, who works at the Institute of Evolutionary Biology (a joint institute between CSIC and Pompeu Fabra University) explains, "This work takes an in-depth look at the process which makes small, isolated populations go through random changes in their genetic variability over time. Present-day Icelanders have been affected by 1,100 years of profound genetic drift. This means they are more similar to each other, yet different to modern populations of continental Europe."
Gender bias
The work, led by researchers from deCODE Genetics- the biotechnology company based in Reykjavik which claims to have genealogical records going back for up to seven centuries in the history of most families on the island, confirms a gender bias in Iceland's population.
"The settlers of Celtic origin had fewer offspring compared with those of Norwegian origin. This is probably because there were more men of Scandinavian origin compared to more women - who would probably have come to the country as slaves and servants - from Scotland and the rest of Britain," explains Lalueza-Fox.
"We have always known that Icelanders descended from Norwegians and Celts, and the analysis of the ancient genomes from the first colonists allows us to see what they were like, both before mixing started, as well as throughout the whole process," explains Sunna Ebeneserdóttir, a researcher from deCODE Genetics. "It's like having a time machine. Now it is possible to study the actual people who participated in the founding of Iceland," adds Agnar Helgason, also from deCODE Genetics, and another of the study's authors.
Iceland, a genetic laboratory
These results provide a detailed view of the origin of a human population, an aspect, according to scientists, which is key to discovering associations of genotype (genetic information in the form of DNA) and phenotype (the expression of the genotype plus the influence of the mean) to continue making advances in finding ways to diagnose, treat and prevent diseases.
"Iceland is big enough for the diseases that affect Europeans to be represented, yet small enough to easily carry out genetic studies which lead to discovering the roots of these complex pathologies. In the not too distant future, we will be able to study the actual individuals who had a certain mutation 1,000 years ago and make a comparison with current patients", concludes the CSIC researcher.

In ancient boulders, new clues about the story of human migration to the Americas

When and how did the first people come to the Americas?

The conventional story says that the earliest settlers came via Siberia, crossing the now-defunct Bering land bridge on foot and trekking through Canada when an ice-free corridor opened up between massive ice sheets toward the end of the last ice age.

But with recent archaeological evidence casting doubt on this thinking, scientists are seeking new explanations. One dominant, new theory: The first Americans took a coastal route along Alaska's Pacific border to enter the continent.

A new geological study provides compelling evidence to support this hypothesis.

By analyzing boulders and bedrock, a research team led by the University at Buffalo shows that part of a coastal migration route became accessible to humans 17,000 years ago. During this period, ancient glaciers receded, exposing islands of southern Alaska's Alexander Archipelago to air and sun -- and, possibly, to human migration.

The timing of these events is key: Recent genetic and archaeological estimates suggest that settlers may have begun traveling deeper into the Americas some 16,000 years ago, soon after the coastal gateway opened up.

The research will be published online on May 30 in the journal Science Advances.

"People are fascinated by these questions of where they come from and how they got there," says lead scientist Jason Briner, PhD, professor of geology in UB's College of Arts and Sciences. "Our research contributes to the debate about how humans came to the Americas. It's potentially adding to what we know about our ancestry and how we colonized our planet."

"Our study provides some of the first geologic evidence that a coastal migration route was available for early humans as they colonized the New World," says UB geology PhD candidate Alia Lesnek, the study's first author. "There was a coastal route available, and the appearance of this newly ice-free terrain may have spurred early humans to migrate southward."

The findings do not mean that early settlers definitely traversed Alaska's southern coast to spread into the Americas: The project examined just one section of the coast, and scientists would need to study multiple locations up and down the coastline to draw firmer conclusions.

Still, the work is exciting because it hints that the seafaring theory of migration is viable.

The bones of an ancient ringed seal -- previously discovered in a nearby cave by other researchers -- provide further, tantalizing clues. They hint that the area was capable of supporting human life at the time that early settlers may have been passing through, Briner says. The new study calculates that the seal bones are about 17,000 years old. This indicates that the region was ecologically vibrant soon after the ice retreated, with resources including food becoming available.

Co-authors on the research included Briner; Lesnek; Charlotte Lindqvist, PhD, an associate professor of biological sciences at UB and a visiting associate professor at Nanyang Technological University; James Baichtal of Tongass National Forest; and Timothy Heaton, PhD, of the University of South Dakota.

A landscape, touched by ice, that tells a story
To conduct their study, the scientists journeyed to four islands within the Alexander Archipelago that lie about 200 miles south/southeast of Juneau.

The team traveled by helicopter to reach these remote destinations. As soon as the researchers arrived, Briner knew that the islands had once been covered by ice.

"The landscape is glacial," he says. "The rock surfaces are smooth and scratched from when the ice moved over it, and there are erratic boulders everywhere. When you are a geologist, it hits you in the face. You know it immediately: The glacier was here."

To pinpoint when the ice receded from the region, the team collected bits of rock from the surfaces of boulders and bedrock. Later, the scientists ran tests to figure out how long the samples -- and thus the islands as a whole -- had been free of ice.

The researchers used a method called surface exposure dating. As Lesnek explains, "When land is covered by a glacier, the bedrock in the area is hidden under ice. As soon as the ice disappears, however, the bedrock is exposed to cosmic radiation from space, which causes it to accumulate certain chemicals on their surface. The longer the surface has been exposed, the more of these chemicals you get. By testing for these chemicals, we were able to determine when our rock surfaces were exposed, which tells us when the ice retreated.

"We use the same dating method for huge boulders called erratics. These are big rocks that are plucked from the Earth and carried to new locations by glaciers, which actually consist of moving ice. When glaciers melt and disappear from a specific region, they leave these erratics behind, and surface exposure dating can tell us when the ice retreated."

For the region that was studied, this happened roughly 17,000 years ago.

The case for a coastal migration route
In recent years, evidence has mounted against the conventional thinking that humans populated North America by taking an inland route through Canada. To do so, they would have needed to walk through a narrow, ice-free ribbon of terrain that appeared when two major ice sheets started to separate. But recent research suggests that while this path may have opened up more than 14,000 years ago, it did not develop enough biological diversity to support human life until about 13,000 years ago, Briner says.

That clashes with archaeological findings that suggest humans were already living in Chile about 15,000 years ago or more and in Florida 14,500 years ago.

The coastal migration theory provides an alternative narrative, and the new study may mark a step toward solving the mystery of how humans came to the Americas.

"Where we looked at it, the coastal route was not only open -- it opened at just the right time," Lindqvist says. "The timing coincides almost exactly with the time in human history that the migration into the Americas is thought to have occurred."

Italy's oldest olive oil discovered in peculiar pot

IMAGE: Chemical analysis conducted on ancient pottery proves olive oil existed in Italy 700 years sooner than what's previously been recorded. view more 

Credit: Polo Regionale di Siracusa per i siti e musei archeologici Museo Paolo Orsi

Olive oil is a staple of Italian cuisine. It's been that way for thousands of years. And new chemical analysis conducted on ancient pottery proves the liquid gold has existed in Italy hundreds of years longer than what anthropologists have previously recorded.

A team of researchers lead by Davide Tanasi, PhD, assistant professor of history at the University of South Florida, carried out chemical analyses to identify the content of a large jar, found in the 90s by Giuseppe Voza during the excavations at the site of Castelluccio. Conservators at the Archaeological Museum of Siracusa restored and reassembled 400 ceramic fragments, resulting in an egg-shaped 3 ½ foot storage container adorned with rope bands and three vertical handles on each side.

At the same architectural site in Castelluccio in Sicily, researchers found two fragmented basins with an internal septum, indicating it was used to keep multiple substances together, but separate, along with a large terracotta cooking plate.

"The shape of this storage container and the nearby septum was like nothing else Voza found at the site in Castelluccio," said Dr. Tanasi. "It had the signature of Sicilian tableware dated to the end of the 3rd and beginning of the 2nd millennium BCE (Early Bronze Age). We wanted to learn how it was used, so we conducted chemical analysis on organic residues found inside."

In the study published in Analytical Methods, Dr. Tanasi tested the three artifacts using techniques traditionally and successfully used on archaeological pottery: Gas Chromatography, Mass Spectrometry and Nuclear Magnetic Resonance. His team found organic residue from all three samples contained oleic and linoleic acids, signatures of olive oil. They conclude the artifacts are from the Sicilian Early Bronze Age due to their location and peculiar shapes.

"The results obtained with the three samples from Castelluccio become the first chemical evidence of the oldest olive oil in Italian prehistory, pushing back the hands of the clock for the systematic olive oil production by at least 700 years," said Tanasi.

The only known identification of chemical signatures of olive oil are from storage jars discovered in southern Italy in Cosenza and Lecce believed to be from the 12th and 11th century BCE (Copper Age).

Wars and clan structure may explain a strange biological event 7,000 years ago

Starting about 7,000 years ago, something weird seems to have happened to men: Over the next two millennia, recent studies suggest, their genetic diversity -specifically, the diversity of their Y chromosomes - collapsed. So extreme was that collapse that it was as if there was only one man left to mate for every 17 women.
Anthropologists and biologists were perplexed, but Stanford researchers now believe they've found a simple - if revealing - explanation. The collapse, they argue, was the result of generations of war between patrilineal clans, whose membership is determined by male ancestors.
The outlines of that idea came to Tian Chen Zeng, a Stanford undergraduate in sociology, after spending hours reading blog posts that speculated - unconvincingly, Zeng thought - on the origins of the "Neolithic Y-chromosome bottleneck," as the event is known. He soon shared his ideas with his high school classmate Alan Aw, also a Stanford undergraduate in mathematical and computational science.
"He was really waxing lyrical about it," Aw said, so the pair took their idea to Marcus Feldman, a professor of biology in Stanford's School of Humanities and Sciences. Zeng, Aw and Feldman published their results May 25 in Nature Communications.
A cultural culprit
It's not unprecedented for human genetic diversity to take a nosedive once in a while, but the Y-chromosome bottleneck, which was inferred from genetic patterns in modern humans, was an odd one. First, it was observed only in men - more precisely, it was detected only through genes on the Y chromosome, which fathers pass to their sons. Second, the bottleneck is much more recent than other biologically similar events, hinting that its origins might have something to do with changing social structures.
Certainly, the researchers point out, social structures were changing. After the onset of farming and herding around 12,000 years ago, societies grew increasingly organized around extended kinship groups, many of them patrilineal clans - a cultural fact with potentially significant biological consequences. The key is how clan members are related to each other. While women may have married into a clan, men in such clans are all related through male ancestors and therefore tend to have the same Y chromosomes. From the point of view of those chromosomes at least, it's almost as if everyone in a clan has the same father.
That only applies within one clan, however, and there could still be considerable variation between clans. To explain why even between-clan variation might have declined during the bottleneck, the researchers hypothesized that wars, if they repeatedly wiped out entire clans over time, would also wipe out a good many male lineages and their unique Y chromosomes in the process.
Computing clans
To test their ideas, the researchers turned to mathematical models and computer simulations in which men fought - and died - for the resources their clans needed to survive. As the team expected, wars between patrilineal clans drastically reduced Y chromosome diversity over time, while conflict between non-patrilineal clans - groups where both men and women could move between clans - did not.
Zeng, Aw and Feldman's model also accounted for the observation that among the male lineages that survived the Y-chromosome bottleneck, a few lineages underwent dramatic expansions, consistent with the patrilineal clan model, but not others.
Now the researchers are looking at applying the framework in other areas - anywhere "historical and geographical patterns of cultural interactions could explain the patterns you see in genetics," said Feldman, who is also the Burnet C. and Mildred Finley Wohlford Professor.
Feldman said the work was a unusual example of undergraduates driving research that was broad both in terms of the academic disciplines spanned - in this case, sociology, mathematics and biology - and in terms of its potential implications for understanding the role of culture in shaping human evolution. And, he said, "Working with these talented guys is a lot of fun."

1,000-year-old mummy found in Peru

A team from the Université libre de Bruxelles's centre for archaeological research (CReA-Patrimoine) has completed a significant excavation in Pachacamac, Peru, where they have discovered an intact mummy in especially good condition. Pachacamac's status as a Pre-Colombian pilgrimage site under the Inca empire. is confirmed by further evidence.

Peter Eeckhout and his team's latest campaign of archaeological excavations has concluded with an exciting surprise: after nine weeks spent exploring the Pre-Colombian site of Pachacamac, in Peru, the researchers from CReA-Patrimoine (ULB Faculty of Philosophy and Social Sciences) have unearthed a mummy in especially good condition. 'The deceased is still wrapped in the enormous funeral bundle that served as a coffin,' points out professor Peter Eeckhout. 'Discoveries like this one are exceptionally scarce, and this mummy is incredibly well preserved. Samples were collected for carbon-14 dating, but the area in which it was discovered and the type of tomb suggest this individual was buried between 1000 and 1200 AD.'

The excavation was carried out as a part of the 'Ychsma' project, named after the region's native people, under the supervision of professor Eeckhout. Three monumental structures were explored during the campaign, including a sanctuary dedicated to the local ancestors. Under Inca rule, in the late 15th century, it appears to have been transformed into a water and healing temple. The archaeologists have discovered many offerings left by worshippers, such as Spondylus shells imported from Ecuador; these are associated with the influx of water during El Niño, and they symbolise fertility and abundance.

Before the Inca settled in the area, the sanctuary included large funerary chambers and numerous mummies, most of which were looted during the Spanish conquest. Miraculously, though, one of the chambers was found intact during the latest round of excavations: this is the funeral chamber that held the mummy. Due to how well it was preserved, the researchers will be able to study it without needing to unwrap the bundle. Together with Christophe Moulherat (Musée du Quai Branly, Paris), they will soon examine the mummy using the latest techniques in medical imaging (X-ray scans, axial tomography, 3D reconstruction, etc.). This will enable them to determine the individual's position, any pathologies they might have suffered from, but also what offerings might be inside the bundle.

The other structures that were excavated are also related to worship: the first one, an Inca monument intended to host pilgrims and rituals, was built in several phases, each identified with a series of offerings such as seashells and precious objects. The last structure explored was probably one of the 'chapels' for foreign pilgrims, referred to by Spanish monk Antonio de la Calancha in his 17th-century description of the site. There, the excavations also uncovered many 'foundation' offerings, including vases, dogs, and other animals, as well as a platform with a hole in the centre, where an idol was likely placed. The complex appears to have been designed around this idol, involved in religious activities with pilgrims.

According to researchers, all these discoveries indicate that Incas made considerable changes to the Pachacamac site, in order to create a large pilgrimage centre on Peru's Pacific coast. 'Deities and their worship played a major part in the life of Pre-Colombian societies,' concludes Peter Eeckhout. 'The Inca understood this very well, and integrated it into how they wielded their power. By promoting empire-wide worship, they contributed to creating a common sense of identity among the many different peoples that made up the empire. Pachacamac is one of the most striking examples of this.'

A shipwreck and an 800-year-old 'made in China' label reveal lost history

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Chinese ceramic bowls in situ at the Java Sea Shipwreck site.

Credit: © The Field Museum, Anthropology, Photographer Pacific Sea Resources

Centuries ago, a ship sank in the Java Sea off the coast of Indonesia. The wooden hull disintegrated over time, leaving only a treasure trove of cargo. The ship had been carrying thousands of ceramics and luxury goods for trade, and they remained on the ocean floor until the 1980s when the wreck was discovered by fishermen. In the years since, archaeologists have been studying artifacts retrieved from the shipwreck to piece together where the ship was from and when it departed. The equivalent of a "Made in China" label on a piece of pottery helped archaeologists reevaluate when the ship went down and how it fits in with China's history.

"Initial investigations in the 1990s dated the shipwreck to the mid- to late 13th century, but we've found evidence that it's probably a century older than that," says Lisa Niziolek, an archaeologist at the Field Museum in Chicago and lead author of the study in the Journal of Archaeological Science: Reports. "Eight hundred years ago, someone put a label on these ceramics that essentially says 'Made in China' -- because of the particular place mentioned, we're able to date this shipwreck better."

The ship was carrying ceramics marked with an inscription that might indicate they were made in Jianning Fu, a government district in China. But after the invasion of the Mongols around 1278, the area was reclassified as Jianning Lu. The slight change in the name tipped Niziolek and her colleagues off that the shipwreck may have occurred earlier than the late 1200s, as early as 1162.

Niziolek notes that the likelihood of a ship in the later "Jianning Lu" days carrying old pottery with the outdated name is slim. "There were probably about a hundred thousand pieces of ceramics onboard. It seems unlikely a merchant would have paid to store those for long prior to shipment -- they were probably made not long before the ship sank," says Niziolek.

Plus, ceramics weren't the only cargo onboard. The ship was also carrying elephant tusks for use in medicine or art and sweet-smelling resin for use in incense or for caulking ships. Both of these materials were critical to re-dating the wreck.

The resins and the tusks come from living things, and all living things contain carbon. A type of carbon atom called C-14 is unstable and decays relatively steadily over time. Scientists can use the amount of C-14 in a sample to determine how old it is. This analysis, known as radiocarbon dating, had been done decades ago and pointed to the shipwreck being about 700-750 years old. However, analytical techniques have improved, and the scientists wanted to see if the date held.

The amount of decayed carbon found in the resins and tusks revealed that the cargo was older than previously thought. When taken together with the place name inscribed on the ceramics, stylistic analysis of ceramics from known time periods, and input from experts overseas, the researchers concluded that the shipwreck was indeed older than previously thought -- somewhere in the neighborhood of 800 years old.

"When we got the results back and learned that the resin and tusk samples were older than previously thought, we were excited," says Niziolek. "We had suspected that based on inscriptions on the ceramics and conversations with colleagues in China and Japan, and it was great to have all these different types of data coming together to support it."

The fact that the Java Sea Shipwreck happened 800 years ago instead of 700 years ago is a big deal for archaeologists.

"This was a time when Chinese merchants became more active in maritime trade, more reliant upon oversea routes than on the overland Silk Road," says Niziolek. "The shipwreck occurred at a time of important transition."

Niziolek also notes the importance of the Java Sea Shipwreck collection. "The salvage company Pacific Sea Resources recovered these artifacts in the 1990s, and they donated them to the Field Museum for education and research. There's often a stigma around doing research with artifacts salvaged by commercial companies, but we've given this collection a home and have been able to do all this research with it. It's really great that we're able to use new technology to re-examine really old materials. These collections have a lot of stories to tell and should not be entirely discounted."

Ancient mound builders carefully timed their occupation of coastal Louisiana site

IMAGE: Hundreds of ancient mound sites, depicted here with yellow triangles, still survive in coastal Louisiana. A new study teases out the natural and human history of one of these mound-top villages, a site known as Grand Caillou, shown in red.

Credit: Graphic by Julie McMahon after Mehta and Chamberlain.

A study of ancient mound builders who lived hundreds of years ago on the Mississippi River Delta near present-day New Orleans offers new insights into how Native peoples selected the landforms that supported their villages and earthen mounds - and why these sites were later abandoned.

The study, reported in the Journal of Island and Coastal Archaeology, also offers a timeline of the natural and human events that shaped one particular site, said University of Illinois anthropology professor Jayur Mehta, who conducted the work with Vanderbilt University postdoctoral researcher Elizabeth Chamberlain while both were at Tulane University in New Orleans.

The site, now known as Grand Caillou, is one of hundreds of mound sites in coastal Louisiana, Mehta said. (Watch a video about the research and history of the site.)

"Louisiana is incredibly important in the history of ancient mound-building cultures," he said. "In what is now the United States, earthen monument and mound construction began on the Louisiana coast."
Ancient peoples began building mounds in North America as early as 4,500 B.C., Mehta said. They often situated their mounds near resource-rich waterways, which could support larger human settlements. As many as 500 people lived at Grand Caillou in its heyday. Some mounds also served ceremonial functions.

That so many mound sites have survived in coastal Louisiana is a testament to their careful construction, Mehta said. Neglect, however, and coastal subsidence - the result of engineered changes to the flow of the Mississippi River - are wearing away at the mounds.

"Louisiana loses about two ancient mounds and/or Native American villages a year," Mehta said.

The researchers used a variety of methods - sediment coring, radiocarbon dating, carbon-isotope analysis, the dating of ceramics found onsite and a method called optically stimulated luminescence - to figure out how and when the land underneath the Grand Caillou mound was formed by natural forces and when the mound builders arrived and established their settlement.

"We wanted to understand at a deeper level how Indigenous peoples of the coast were choosing where to build their villages," Mehta said.

Grand Caillou is situated on a natural levee of the Lafourche sub-delta, one of several major lobes of the Mississippi River Delta near New Orleans. Fed by sediments deposited by the river, Lafourche expanded in size over a period of several hundred years, a process that ended at about 800 A.D., the researchers found. The mound builders set up their village around 1200 A.D., long after the site was stable and covered over with vegetation, the team found.

Core samples and excavations revealed that the mound was built in distinct layers, with clay on the bottom, looser sediments piled in the middle and a clay cap on top. This finding confirms earlier archaeological reports that ancient mounds were engineered in layers to withstand the elements.
"The way they were constructed contributes to their durability," Mehta said.

The Grand Caillou mound was built on top of a river deposit that was naturally higher than surrounding land.

"It's only a few feet higher than nearby areas," Mehta said. "But in a landscape where there's no topography, one or two feet can make a world of difference."

Ceramics found at the site date to between 1000 and 1400 A.D. Radiocarbon dating of charcoal found evidence that the site was abandoned by about 1400. By looking at ratios of carbon isotopes - carbon atoms with differing masses - the team saw changes over time that were likely the result of saltwater incursion into the area. These changes coincided with the ultimate abandonment of the village site.

The new study is a much-needed addition to research on threatened cultural sites in coastal regions, said University of Tennessee anthropology professor David G. Anderson, an expert on U.S. Paleoindian archaeology who was not involved in the research.

"We are facing the loss of much of the record of human settlement and use of coastal zones - and must take steps to address the challenge," Anderson said. "Mehta and Chamberlain's study exemplifies the kind of work that will be needed."

When farmers migrated to southeast Asia, according to the DNA

By analyzing genome-wide DNA from the remains of ancient Southeast Asian individuals, scientists have shed new light on the past 4,000 years of genetic history from the region. Their analysis helps reveal potential migration events that may have led to the region's rich cultural and linguistic diversity observed today.

Southeast Asia has a complex history of human occupation, yet studying this history through genetics has remained a challenge because, for one, its humid and tropical environment presents unfavorable conditions for DNA preservation. As such, hypotheses based on archaeological findings - predicting the human origins of cultural shifts (like the use of tools and pottery) brought on by the introduction of farming, for example - remain unresolved by genetic studies.

Here, Mark Lipson, David Reich and colleagues obtained DNA data of 18 ancient Southeast Asian individuals from the Neolithic period to the Iron Age (4,100 to 1,700 years ago), found in modern-day Vietnam, Myanmar, Thailand and Cambodia.

With additional support from archaeological and linguistic data, the researchers identified two major waves of genetic mixture indicative of specific migration events. The first wave, occurring during the Neolithic period, consisted of early farmer migrants from South China who mixed with local Southeast Asian hunter-gatherers.

A couple thousand years afterwards, during the Bronze Age, an additional "pulse" of genes flowed from China to Southeast Asia, reflecting another influx of farmers, the researchers say. Interestingly, the pattern of human movement in Southeast Asia parallels that observed in Europe, where ancient DNA studies have also revealed genetic mixture associated with transitions in agricultural culture.

Details:


An international team led by researchers at HMS and the University of Vienna extracted and analyzed DNA from the remains of 18 people who lived between about 4,100 and 1,700 years ago in what are now Vietnam, Thailand, Myanmar and Cambodia.

The team found that the first migration took place about 45,000 years ago, bringing in people who became hunter-gatherers.

Then, during the Neolithic Period, around 4,500 years ago, there was a large-scale influx of people from China who introduced farming practices to Southeast Asia and mixed with the local hunter-gatherers.

People today with this ancestry mix tend to speak Austroasiatic languages, leading the researchers to propose that the farmers who came from the north were early Austroasiatic speakers.

"This study reveals a complex interplay between archaeology, genetics and language, which is critical for understanding the history of Southeast Asian populations," said co-senior author Ron Pinhasi of the University of Vienna.

The research revealed that subsequent waves of migration during the Bronze Age, again from China, arrived in Myanmar by about 3,000 years ago, in Vietnam by 2,000 years ago and in Thailand within the last 1,000 years. These movements introduced ancestry types that are today associated with speakers of different languages.

The identification of three ancestral populations--hunter-gatherers, first farmers and Bronze Age migrants--echoes a pattern first uncovered in ancient DNA studies of Europeans, but with at least one major difference: Much of the ancestral diversity in Europe has faded over time as populations mingled, while Southeast Asian populations have retained far more variation.

"People who are nearly direct descendants of each of the three source populations are still living in the region today, including people with significant hunter-gatherer ancestry who live in Thailand, Malaysia, the Philippines and the Andaman Islands," said Reich, professor of genetics at HMS and co-senior author of the study. "Whereas in Europe, no one living today has more than a small fraction of ancestry from the European hunter-gatherers."

Reich hypothesizes that the high diversity of Southeast Asia today can be partly explained by the fact that farmers arrived much more recently than in Europe--around 4,500 years ago compared with 8,000 years ago--leaving less time for populations to mix and genetic variation to even out.
The new findings make it clear that the multiple waves of migration, each of which occurred during a key transition period of Southeast Asian history, shaped the genetics of the region to a remarkable extent.

"The major population turnover that came with the arrival of farmers is unsurprising, but the magnitudes of replacement during the Bronze Age are much higher than many people would have guessed," said Reich.

Also unexpected were the linguistic implications raised by analyses of the ancestry of people in western Indonesia.

"The evidence suggests that the first farmers of western Indonesia spoke Austroasiatic languages rather than the Austronesian languages spoken there today," Reich added. "Thus, Austronesian languages were probably later arrivals."

Additional samples from western Indonesia before and after 4,000 years ago should settle the question, Reich said.

Ancient human remains and a mystery: Cornish barrow gives up 4,000-year-old secrets

IMAGE: ANU Archaeologist Dr Catherine Frieman & co-director James Lewis with funerary pot in situ. view more 

Credit: (c)SEKAS

An archaeologist from The Australian National University (ANU) has hailed her excavation of a Bronze Age burial mound in south west England a huge success with the discovery of an intact 4,000 year old human cremation as well as evidence of unaccountable activity from the medieval period on the same site.

Dr Catherine Frieman recently excavated an untouched ancient barrow near the town of Looe in South East Cornwall. Her 14 day-dig over Easter was the first time such a site in the area has been excavated to modern archaeological standards.

She said when digging began, local farmers told her they'd ploughed the field in their childhood, so she didn't expect the site to be so well preserved.

"We were so excited to find such a lot of archaeology on the site despite scores of generations of ploughing, but to find an intact clay urn buried 4,000 years ago just 25 centimetres beneath the surface is nothing short of a miracle," said Dr Frieman.

This and other evidence from the site has led her to conclude there was most likely a large mound over the burial which existed from prehistory well into the middle ages protecting the centre of the barrow.

"This is a sealed, intact cremation so it has the potential to tell us a lot about the cremation rite as it was practiced 4,000 years ago. We also appear to have some identifiable fragments of bone among the cremated remains so we'll potentially be able to tell a lot about the individual themselves," she said.

"We'll be able to say what gender they were, possibly their age, or an age range, and depending on the bone preservation we can conduct analyses to examine where they were from, what their diet was like, where this food was coming from and what they ate and drank as a child when their teeth were forming. This is a very beautiful, very complete burial, and we're very excited," she said.

Other items found include various examples of Cornish Bronze Age pottery, flint tools and two high-quality hammer stones, used to make flint tools. However, what has puzzled Dr Frieman and her team was the discovery of medieval activity on the same site.

"The site has thrown up a big mystery for us because we found what we believe is an entire - albeit crushed - medieval pot from the 12th or 13th century AD, carefully placed under a couple of layers of flat stones. It had some cooked food remains adhering to it and we don't know what it's doing there or why."

"Hundreds of years after the barrow was built, someone from the 12th or 13th century came back to this site and dug into it to bury this pot.

"At that stage there were two local monasteries in view of this site, as Looe Island was a satellite monastery of the Glastonbury Abbey, so it would be very strange to have non-Christian activity on this site. The evidence looks quite ritualistic, but what the ritual was, we don't know," she said.
The team also excavated a round house - an ancient dwelling or land marker nearby, possibly from 500 BC and are trying to deduce possible reasons for the location of the barrow.

"This was a traversed place and regularly visited over the millennia, it affords a sweeping view of the south coast of England and we know that there are a series of Bronze Age shipwrecks off this coast, so this was an important shipping highway in prehistory."

The analysis of soil, pollen, flint and other samples is underway but it will probably be a year before a comprehensive story of the find is possible.

Dr Frieman said the dig would not have been possible without the help of a team of enthusiastic and skilled volunteers from the Cornwall Archaeological Society, the tenant farmers, John and Vanessa Hutchings and the strong support of the National Trust who own and manage the site and their Regional Archaeologist James Parry.

The excavation was funded through a Discovery Early Career Researcher Award (DECRA) and a contribution from the ANU College of Archaeology and Anthropology.

Archaeologists uncover earliest evidence for equid bit wear in the ancient Near East

An international team of archaeologists has uncovered the earliest example of the use of a bridle bit with an equid (horse family) in the Near East. The discovery provides first evidence of the use of the bit (mouth piece) to control an animal long before the appearance of the horse in the Near East.

Evidence of the bridle bit was derived from the skeleton of a donkey dating to the Early Bronze Age III (approximately 2700 BCE) found at the excavations of the biblical city Gath (modern Tell es-Safi) of the Philistines, the home of Goliath, located in central Israel. The donkey was laid as a sacrificial offering before the construction of a house in a domestic neighborhood.

The international team, including archaeologists from Bar-Ilan University, the University of Manitoba (St. Paul's College), University of Saskatchewan (St. Thomas More College), Ariel University and Grand Valley State University published their findings today in the journal PLOS ONE.

"This is significant because it demonstrates how early domestic donkeys were controlled, and adds substantially to our knowledge of the history of donkey (Equus asinus) domestication and evolution of riding and equestrian technology. It is also significant that it was discovered on the remains of an early domestic donkey that was sacrificed probably as an offering to protect what we interpret to be a merchant domestic residence uncovered during our excavations," said Prof. Haskel Greenfield, of the University of Manitoba, the paper's lead author.

"The use of a bridle bit on a donkey during this period is surprising, since it was commonly assumed that donkeys were controlled with nose rings, as depicted in Mesopotamian art," said Prof. Aren Maeir, from Bar-Ilan University's Martin (Szusz) Department of Land of Israel Studies and Archaeology. Prof. Maeir has led the Tell es-Safi/Gath Archaeological Project since its inception more than 20 years ago. The excavations take place every summer in the Tel Zafit National Park, about halfway between Jerusalem and the coastal city of Ashkelon.

The authors propose that the wear on the tooth of the donkey was made with a soft bit, likely made from rope or wood. "Only later, from the Middle Bronze Age and onward (after 2000 BCE), was it thought that bits, in particular metal bits, were used - first with horses that were introduced to the Near East at the time, and subsequently with other equids, such as donkeys," added Maeir. Examples of these later bits were found in Israel at Tel Haror.

The donkey is one of four that were found buried under neighborhood houses, which indicates the importance of the donkey in this society -- most likely as a beast of burden used in trade, the researchers said.

In a previously-published study the researchers provided evidence, based on isotopic analyses, that this very donkey was born in Egypt and brought to Canaan sometime during its lifetime. This demonstrates that this animal -- and most likely others -- was transported over large distances. Using bits allowed donkey herders to control the animals more easily during their transport.

Studies of the dental isotopes from the same donkey demonstrate, as well, that it was born and raised in Egypt and brought to the site only in the last few months of its life, before it was sacrificed and buried beneath the floor of the house as it was being rebuilt. Domestic horses were not yet present in the Near East at that time. As a result, donkeys were not only used as beasts of burden, but also were used to pull and be ridden by the newly emerging elites in these early city-states.

Lead pollution in Greenland ice shows rise and fall of ancient European civilizations

To learn about the rise and fall of ancient European civilizations, researchers sometimes find clues in unlikely places: deep inside of the Greenland ice sheet, for example.

Thousands of years ago, during the height of the ancient Greek and Roman empires, lead emissions from sources such as the mining and smelting of lead-silver ores in Europe drifted with the winds over the ocean to Greenland - a distance of more than 2800 miles (4600 km) - and settled onto the ice. Year after year, as fallen snow added layers to the ice sheet, lead emissions were captured along with dust and other airborne particles, and became part of the ice-core record that scientists use today to learn about conditions of the past.

In a new study published in PNAS, a team of scientists, archaeologists and economists from the Desert Research Institute (DRI), the University of Oxford, NILU - Norwegian Institute for Air Research and the University of Copenhagen used ice samples from the North Greenland Ice Core Project (NGRIP) to measure, date and analyze European lead emissions that were captured in Greenland ice between 1100 BC and AD 800. Their results provide new insight for historians about how European civilizations and their economies fared over time.

"Our record of sub-annually resolved, accurately dated measurements in the ice core starts in 1100 BC during the late Iron Age and extends through antiquity and late antiquity to the early Middle Ages in Europe - a period that included the rise and fall of the Greek and Roman civilizations," said the study's lead author Joe McConnell, Ph.D., Research Professor of Hydrology at DRI. "We found that lead pollution in Greenland very closely tracked known plagues, wars, social unrest and imperial expansions during European antiquity."

A previous study from the mid-1990s examined lead levels in Greenland ice using only 18 measurements between 1100 BC and AD 800; the new study provides a much more complete record that included more than 21,000 precise lead and other chemical measurements to develop an accurately dated, continuous record for the same 1900-year period.

To determine the magnitude of European emissions from the lead pollution levels measured in the Greenland ice, the team used state-of-the-art atmospheric transport model simulations.

"We believe this is the first time such detailed modeling has been used to interpret an ice-core record of human-made pollution and identify the most likely source region of the pollution," said coauthor Andreas Stohl, Ph.D., Senior Scientist at NILU.

Most of the lead emissions from this time period are believed to have been linked to the production of silver, which was a key component of currency.

"Because most of the emissions during these periods resulted from mining and smelting of lead-silver ores, lead emissions can be seen as a proxy or indicator of overall economic activity," McConnell explained.

Using their detailed ice-core chronology, the research team looked for linkages between lead emissions and significant historical events.

Their results show that lead pollution emissions began to rise as early as 900 BC, as Phoenicians expanded their trading routes into the western Mediterranean. Lead emissions accelerated during a period of increased mining activity by the Carthaginians and Romans primarily in the Iberian Peninsula, and reached a maximum under the Roman Empire.

The team's extensive measurements provide a different picture of ancient economic activity than previous research had provided. Some historians, for example, had argued that the sparse Greenland lead record provided evidence of better economic performance during the Roman Republic than during the Roman Empire.

According to the findings of this study, the highest sustained levels of lead pollution emissions coincided with the height of the Roman Empire during the 1st and 2nd centuries AD, a period of economic prosperity known as the Pax Romana. The record also shows that lead emissions were very low during the last 80 years of the Roman Republic, a period known as the Crisis of the Roman Republic.

"The nearly four-fold higher lead emissions during the first two centuries of the Roman Empire compared to the last decades of the Roman Republic indicate substantial economic growth under Imperial rule," said coauthor Andrew Wilson, Professor of the Archaeology of the Roman Empire at Oxford.

The team also found that lead emissions rose and fell along with wars and political instability, particularly during the Roman Republic, and took sharp dives when two major plagues struck the Roman Empire in the 2nd and 3rd centuries. The first, called the Antonine Plague, was probably smallpox. The second, called the Plague of Cyprian, struck during a period of political instability called the third-century crisis.

"The great Antonine Plague struck the Roman Empire in AD 165 and lasted at least 15 years. The high lead emissions of the Pax Romana ended exactly at that time and didn't recover until the early Middle Ages more than 500 years later," Wilson explained.

The research team for this study included ice-core specialists, atmospheric scientists, archaeologists, and economic historians - an unusual combination of expertise.

"Working with such a diverse team was a unique experience in my career as a scientist," McConnell said. "I think that our results show that there can be great value in collaborating across disciplines."

Where hominid brains are concerned, size doesn't matter

The human-like features of Homo nalei's brain surprise research team that examined fossil's brain imprints

University of the Witwatersrand

IMAGE: The skulls of Homo naledi bear traces on their inside surfaces of the shape of naledi's brain. Only a third the size of human brains, they nonetheless had some surprisingly... view more 

Credit: Credit: John Hawks

The recently-discovered species Homo naledi may have had a pint-sized brain, but that brain packed a big punch. New research by Ralph Holloway and colleagues - that include researchers from the University of the Witwatersrand, Johannesburg, South Africa - published in the Proceedings of the National Academy of Sciences examines the imprints of the brain upon the skulls of this species, called endocasts. The research highlights the humanlike shape of naledi's tiny brain, surprising scientists who studied the fossils. These findings draw further into question the long-held belief that human evolution was an inevitable march towards bigger, more complex brains.
The discovery of Homo naledi by Professor Lee Berger of Wits University and his team at the Rising Star caves in the Cradle of Human Kind in 2013 was one of the largest hominin discoveries ever made and hailed as one of the most significant hominid discoveries of the 21st Century. Berger and Professor John Hawkes who was also part of the original Rising Star team who made the naledi discovery, as well as Professor Heather Garvin from Des Moines University in the US, are associated with the Evolutionary Studies Institute (ESI), based at Wits University. They are all co-authors of the current study.
In 2017, geologists demonstrated that this species existed in southern Africa between 236,000 and 335,000 years ago--potentially the same time that modern humans first emerged in Africa. This is a puzzle to scientists, who long held that there was only one species in Africa at this late time period - Homo sapiens. How did this species exist alongside others with brains three times its size? The new study suggests that naledi's behavior may have reflected the shape and structure of the brain more than its size.
The researchers pieced together traces of Homo naledi's brain shape from an extraordinary collection of skull fragments and partial crania, from at least five adult individuals. One of these bore a very clear imprint of the convolutions on the surface of the brain's left frontal lobe. "This is the skull I've been waiting for my whole career," said lead author Ralph Holloway, of Columbia University.
The anatomy of naledi's frontal lobe was similar to humans, and very different from great apes. Naledi wasn't alone. Other members of our genus, from Homo erectus to Homo habilis and the small-brained "hobbits", Homo floresiensis, also share features of the frontal lobe with living humans. But earlier human relatives, like Australopithecus africanus, had a much more apelike shape in this part of the brain, suggesting that functional changes in this brain region emerged with Homo. "It's too soon to speculate about language or communication in Homo naledi," said coauthor Shawn Hurst, "but today human language relies upon this brain region."
The back of the brain also showed humanlike changes in naledi compared to more primitive hominins like Australopithecus. Human brains are usually asymmetrical, with the left brain displaced forward relative to the right. The team found signs of this asymmetry in one of the most complete naledi skull fragments. They also found hints that the visual area of the brain, in the back of the cortex, was relatively smaller in naledi than in chimpanzees--another humanlike trait.
The small brains of Homo naledi raise new questions about the evolution of human brain size. Big brains were costly to human ancestors, and some species may have paid the costs with richer diets, hunting and gathering, and longer childhoods. But that scenario doesn't seem to work well for Homo naledi, which had hands well-suited for toolmaking, long legs, humanlike feet, and teeth suggesting a high-quality diet. According to study coauthor John Hawks, "Naledi's brain seems like one you might predict for Homo habilis, two million years ago. But habilis didn't have such a tiny brain--naledi did."
A humanlike brain organisation might mean that naledi shared some behaviours with humans despite having a much smaller brain size. Lee Berger, a co-author on the paper, suggests that the recognition of naledi's small but complex brain will also have a significant impact on the study of African archaeology. "Archaeologists have been too quick to assume that complex stone tool industries were made by modern humans. With naledi being found in southern Africa, at the same time and place that the Middle Stone Age industry emerged, maybe we've had the story wrong the whole time."

How our ancestors with autistic traits led a revolution in Ice Age art

IMAGE: This is a drawing of a horse by Nadia, a gifted autistic child artist (left) and by a typically developing child of the same age (right). view more 

Credit: Penny Spikins, University of York

The ability to focus on detail, a common trait among people with autism, allowed realism to flourish in Ice Age art, according to researchers at the University of York.

Around 30,000 years ago realistic art suddenly flourished in Europe. Extremely accurate depictions of bears, bison, horses and lions decorate the walls of Ice Age archaeological sites such as Chauvet Cave in southern France.

Why our ice age ancestors created exceptionally realistic art rather than the very simple or stylised art of earlier modern humans has long perplexed researchers.

Many have argued that psychotropic drugs were behind the detailed illustrations. The popular idea that drugs might make people better at art led to a number of ethically-dubious studies in the 60s where participants were given art materials and LSD.

The authors of the new study discount that theory, arguing instead that individuals with "detail focus", a trait linked to autism, kicked off an artistic movement that led to the proliferation of realistic cave drawings across Europe.

Lead author of the paper, Dr Penny Spikins from the Department of Archaeology at the University of York, said: "Detail focus is what determines whether you can draw realistically; you need it in order to be a talented realistic artist. This trait is found very commonly in people with autism and rarely occurs in people without it.

"We looked at the evidence from studies attempting to identify a link between artistic talent and drug use, and found that drugs can only serve to dis-inhibit individuals with a pre-existing ability. The idea that people with a high degree of detail focus, many of which may have had autism, set a trend for extreme realism in ice age art is a more convincing explanation."

The research adds to a growing body of evidence that people with autistic traits played an important role in human evolution.

Dr Spikins added: "Individuals with this trait - both those who would be diagnosed with autism in the modern day and those that wouldn't - likely played an important part in human evolution and survival as we colonised Europe.

"As well as contributing to early culture, people with the attention to detail needed to paint realistic art would also have had the focus to create complex tools from materials such as bone, rock and wood. These skills became increasingly important in enabling us to adapt to the harsh environments we encountered in Europe."

Prehispanic Andean concepts of death and renewal

Research in the Andes has yielded evidence for a complex association between settlement sites and mortuary monuments, tied to concepts of death, ancestor veneration and water.

In the case-study Carved Rocks and Subterranean Burials at Kipia, Ancash, AD 1000 - 1532 published in De Gruyter's journal Open Archaeology, authors Kevin Lane, Emma Pomeroy and Milton Reynaldo Lújan Davila analyse the Prehispanic-Spanish Colonial multi-faceted site of Kipia, in the Ancash highlands in Peru.

The site contains two small settlements, a cosmological centre, and a funerary sector of subterranean tombs. The author's study reveals the stunning relation between ceremonial sites and cemeteries which underpins complex Andean concepts of death and renewal.

The authors paid special attention to the cosmological core of the site, which is arranged around a series of carved rocks - huanca -, a central huaca ¬(deity/ancestor), and a communal subterranean tomb. It was discovered that the various features of the site can be related to the surrounding landscape, which is remarkable since archaeological examples establishing a direct link between site and landscape in the Andes are not common. Even more remarkable is the fact that the discovery is supplemented by bioarchaeological data (the analyzed subterranean tomb - pukullo - presented in the research).

In the Prehispanic Andes the landscape was innately animated, and Kipia is positioned at the center of its particular physical environment. In this sense, Kipia was not just a repository for the dead, but more widely a place of communion between the living and the departed, associated to the central huaca-huanca, and the other carved rock-faces.

The importance of Kipia lies in its role as a local huaca dedicated to the lightening deity in which overt manifestations of life and death cohabited. In turn, Kipia linked into a network of other larger potentially sacred sites, such as the lakes.

Excavated, comparative highland Late Intermediate Period (AD 1000-1450) tombs are limited, especially ones linked to important sacred sites. In synthesis, this study makes a valuable contribution to the very limited literature on the use of communal burial structures in the Andes that is based on excavation, detailed osteological analysis and is in direct connection with a particular sacred landscape.

Dr. Alexis Mantha, an expert on Andean Archeology from Université Montréal, outlines: "This article provides a very interesting and rare case study of a complex animated ritual landscape in the highlands of Ancash, Peru, during late Andean prehistory. The authors convincingly examine the intricate ritual relationships among the skeletal content of a subterranean tomb (pukullo) and other features of the surrounding landscape such as a stone monolith (huanca), peaks and highland lakes."

A European origin for leprosy?

IMAGE: Skeletal remains showing evidence of leprosy from the Odense St. Jørgen cemetery in Denmark, which was established in 1270 and existed until 1560. view more 

Credit: Dorthe Dangvard Pedersen

New research by an international team including scientists from the Max Planck Institute for the Science of Human History, the University of Tübingen, EPFL Lausanne and the University of Zurich has revealed that there was much more diversity in the leprosy strains circulating in Medieval Europe than previously thought. This finding, based on the sequencing of 10 new ancient genomes from the leprosy-causing bacterium Mycobacterium leprae, complicates prior assumptions about the origin and spread of the disease, and also includes the oldest M. leprae genome sequenced to date, from about 400 AD in the United Kingdom.
Leprosy is one of the oldest recorded and most stigmatized diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries, with over 200,000 new cases reported annually. The bacterium Mycobacterium leprae is the main cause of leprosy. Previous research on the bacterium suggested that it clusters into several strains, only two of which were present in Medieval Europe. The present study, published in the journal PLOS Pathogens, aimed to further investigate the history and origin of M. leprae by looking for genetic evidence from a large number of ancient samples from throughout Europe.
10 new ancient genomes of M. leprae dating from approximately 400-1400 AD The current study examined approximately 90 individuals with skeletal deformations that were characteristic of leprosy, from across Europe and from time periods ranging from approximately 400 AD to 1400 AD. From these samples, 10 new medieval M. leprae genomes were fully reconstructed. These genomes represent all known strains, including strains that are today associated with different locations around the globe, including Asia, Africa and the Americas. Additionally, in this study multiple strains were often found in the same cemetery, illustrating the diversity of the leprosy strains circulating throughout the continent at the time.
"We found much more genetic diversity in ancient Europe than expected," explains Johannes Krause, senior author of the study and a director at the Max Planck Institute for the Science of Human History. "Additionally, we found that all known strains of leprosy are present in Medieval Europe, suggesting that leprosy may already have been widespread throughout Asia and Europe in antiquity or that it might have originated western Eurasia."
Oldest leprosy genome to date One M. leprae genome reconstructed by the team was from Great Chesterford, England, and dates to between 415-545 AD. This is the oldest M. leprae genome sequenced to date and comes from one of the oldest known cases of leprosy in the United Kingdom. Interestingly, this strain is the same found in modern-day red squirrels and supports the hypothesis that squirrels and the squirrel fur trade were a factor in the spread of leprosy among humans in Europe during the medieval period.
"The dynamics of M. leprae transmission throughout human history are not fully resolved. Characterization and geographic association of the most ancestral strains are crucial for deciphering leprosy's exact origin" states lead author Verena Schuenemann of the University of Zurich. "While we have some written records of leprosy cases that predate the Common Era, none of these have yet been confirmed on a molecular level."
The abundance of ancient genomes in the current study has resulted in a new and older estimate for the age of M. leprae than previous studies, placing its age at least a few thousand years old. "Having more ancient genomes in a dating analysis will result in more accurate estimates," explains Krause. "The next step is to search for even older osteological cases of leprosy than currently available, using well-established methods for identification of potential cases."

78,000 year cave record from East Africa shows early cultural innovations

Kenyan cave sheds new light on dawn of modern man

Australian National University

IMAGE: Items found in Panga ya Saidi cave. 1. A decorated bone 2. A broken bone arrow point 3. An awl made of tusk 4. An ochre crayon. 5-9. Ostrich egg shell beads,... view more 

Credit: Credit Francesco d'Errico and Africa Pitarch Marti.

Forty-eight thousand year-old crayons and shell beads were among a treasure trove of items unearthed by archaeologists at a cave in Kenya.

Archaeologists have discovered more than 30,000 items at the site which is shedding new light on the crucial time period when Homo sapiens first started showing signs of modern behaviour.

The research was led by archaeologist Dr Ceri Shipton of The Australian National University (ANU) School of Culture, History and Language, who said the Panga ya Saidi cave sequence dates back 78,000 years and is the only known site in East Africa with an unbroken archaeological record of human inhabitation.

"It is the most beautiful site I have ever worked on. As soon as I saw it I knew it was special," Dr Shipton said.

"It has a continuous record with people there right up until 500 years ago.

"The site has amazing levels of preservation with so many of the artefacts in mint condition."
Dr Shipton said the site, on the Kenyan south coast just north of Mombasa, was providing new insights into the Later Stone Age - a period of time beginning about 67,000 years ago associated with the rise of modern human behaviour and culture in Africa.

"You start to see things like decorated bones, beads made from marine shell or ostrich eggs, miniaturized stone tools, and bones carved into things like arrow points. This is the oldest date we have for when this behaviour is first observed," he said.

"Previous sites relating to this early period of modern human behaviour have all been in South Africa and the East African Rift Valley, this is the first site on the coast of East Africa and the first with such a continuous record."

Dr Shipton said it was highly unusual to find a site where early Homo sapiens were living in a tropical forest.

"Early humans liked to be on open grassland where there is a lot of large animals for hunting," Dr Shipton said.

"These people were living in tropical forest hunting smaller animals like monkeys and small deer, animals you may need more sophisticated technology to catch."

"What is striking about this record is the innovations you see in technology and material culture, and the ability to exploit both forest and savannah environments. It is this kind of behavioural flexibility that allowed our species to populate the rest of the world outside of Africa."

Professor Andy Herries from La Trobe University Archaeology undertook archaeomagnetic analysis of the cave sediments which showed that the transition in stone tool technology took place during a particularly cold and dry glacial period.

"the site documents the earliest evidence of this style of microlithic Later Stone Age technology and shows how early modern humans were able to adapt to a range of new environments at this time," Professor Herries said.

"It is a small precursor to our eventual habitation of every corner and environment on the planet."
Of more than 30,000 items found at the site, some of the most remarkable include 48,000 year old red ochre crayons and engraved bones. Dr Shipton was struck by the high-level preservation of the artefacts.

"The stone tools are still sharp. The beads and engraved bones have survived intact which is really rare," he said.

"On the crayons we can still see the grooves where they have been used. They're in the same condition now as when people discarded them."

The study was published on Wednesday in the Nature Communications journal. The project was led by the Max Planck Institute for the Science of Human History.

IMAGE: The first substantial cave record from coastal Kenya ranges from the Middle Stone Age to the Iron Age, showing gradual changes in cultural, technological and symbolic innovations beginning at 67,000... view more 

Credit: Mohammad Shoaee

An international, interdisciplinary group of scholars working along the East African coast have discovered a major cave site which records substantial activities of hunter-gatherers and later, Iron Age communities. Detailed environmental research has demonstrated that human occupations occur in a persistent tropical forest-grassland ecotone, adding new information about the habitats exploited by our species, and indicating that populations sought refuge in a relatively stable environment. Prior to this cave excavation, little information was available about the last 78,000 years from coastal East Africa, with the majority of archaeological research focused on the Rift Valley and in South Africa.

Humans lived in the humid coastal forest
 
A large-scale interdisciplinary study, including scientific analyses of archaeological plants, animals and shells from the cave indicates a broad perseverance of forest and grassland environments. As the cave environment underwent little variation over time, humans found the site attractive for occupation, even during periods of time when other parts of Africa would have been inhospitable.

This suggests that humans exploited the cave environment and landscape over the long term, relying on plant and animal resources when the wider surrounding landscapes dried. The ecological setting of Panga ya Saidi is consistent with increasing evidence that Homo sapiens could adapt to a variety of environments as they moved across Africa and Eurasia, suggesting that flexibility may be the hallmark of our species. Homo sapiens developed a range of survival strategies to live in diverse habitats, including tropical forests, arid zones, coasts and the cold environments found at higher latitudes.

Technological innovations occur at 67,000 years ago

Carefully prepared stone tool toolkits of the Middle Stone Age occur in deposits dating back to 78,000 years ago, but a distinct shift in technology to the Later Stone Age is shown by the recovery of small artefacts beginning at 67,000 years ago. The miniaturization of stone tools may reflect changes in hunting practices and behaviors. The Panga ya Saidi sequence after 67,000, however, has a mix of technologies, and no radical break of behavior can be detected at any time, arguing against the cognitive or cultural 'revolutions' theorized by some archaeologists. Moreover, no notable break in human occupation occurs during the Toba volcanic super-eruption of 74,000 years ago, supporting views that the so-called 'volcanic winter' did not lead to the near-extinction of human populations, though hints of increased occupation intensity from 60,000 years ago suggests that populations were increasing in size.

Earliest symbolic and cultural items found at Panga ya Saidi cave

The deep archaeological sequence of Panga ya Saidi cave has produced a remarkable new cultural record indicative of cultural complexity over the long term. Among the recovered items are worked and incised bones, ostrich eggshell beads, marine shell beads, and worked ochre. Panga ya Saidi has produced the oldest bead in Kenya, dating to ~65,000 years ago. At about 33,000 years ago, beads were most commonly made of shells acquired from the coast. While this demonstrates contact with the coast, there is no evidence for the regular exploitation of marine resources for subsistence purposes.

Ostrich eggshell beads become more common after 25,000 years ago, and after 10,000 years ago, there is again a shift to coastal shell use. In the layers dating to between ~48,000 to 25,000 years ago, carved bone, carved tusk, a decorated bone tube, a small bone point, and modified pieces of ochre were found. Though indicative of behavioral complexity and symbolism, their intermittent appearance in the cave sequence argues against a model for a behavioral or cognitive revolution at any specific point in time.

Project Principal Investigator and Director of the Department of Archaeology at the Max Planck Institute for the Science of Human History Dr. Nicole Boivin states, "The East African coastal hinterland and its forests and have been long considered to be marginal to human evolution so the discovery of Panga ya Saidi cave will certainly change archaeologists' views and perceptions."
Group Leader of the Stable Isotopes Lab Dr. Patrick Roberts adds, "Occupation in a tropical forest-grassland environment adds to our knowledge that our species lived in a variety of habitats in Africa."

"The finds at Panga ya Saidi undermine hypotheses about the use of coasts as a kind of 'superhighway' that channeled migrating humans out of Africa, and around the Indian Ocean rim," observes Professor Michael Petraglia.

New research shows how Indo-European languages spread across Asia

A new study has discovered that horses were first domesticated by descendants of hunter-gatherer groups in Kazakhstan who left little direct trace in the ancestry of modern populations. The research sheds new light on the long-standing "steppe theory" on the origin and movement of Indo-European languages made possible by the domestication of the horse.

The domestication of the horse was a milestone in human history that allowed people, their languages, and their ideas to move further and faster than before, leading both to widespread farming and to horse-powered warfare.

Scholars from around the world have collaborated on a new inter-disciplinary research project, which was published in the journal Science 9 May 2018. The researchers analysed ancient and modern DNA samples from humans and compared the results - the 74 ancient whole-genome sequences studied by the group were up to 11,000 years old and were from inner Asia and Turkey.

Professor Eske Willerslev, who holds positions both at St John's College, University of Cambridge, and the University of Copenhagen, jointly led the study which looked at archaeological findings, history, and linguistics.

Much of the study builds on questions raised by scholars of Indo-European studies at the Institute of Nordic Studies and Linguistics at University of Copenhagen. A number of conflicting theories have been presented about who first domesticated the horse, with previous studies pointing to people of the pastoralist Yamnaya culture, a dominant herding group who lived in Eastern Europe and Western Asia.

Dr. Guus Kroonen, historical linguist at University of Copenhagen, explains:

"The successful spread of the Indo-European languages across Eurasia has puzzled researchers for a century. It was thought that speakers of this language family played a key role in the domestication of the horse, and that this, in combination with the development of wheeled vehicles, allowed them to spread across Eurasia from the Yamnaya culture."

However, as this study shows, domesticated horses were used by the Botai people already 5,500 years ago, and much further East in Central Asia, completely independent of the Yamnaya pastoralists. A further twist to the story is that the descendants of these Botai were later pushed out from the central steppe by migrations coming from the west. Their horses were replaced too, indicating that horses were domesticated separately in other regions as well.

No link between Botai and Yamnaya cultures
The study does not find a genetic link between the people associated with the Yamnaya and Botai archaeological cultures, which is critical to understanding the eastward movement of the Yamnaya. Apparently, their eastward expansion bypassed the Botai completely, moving 3000 kilometres across the steppe to the Altai Mountains in Central and East Asia.

Professor Alan Outram from the Department of Archaeology at the University of Exeter and one of the paper's authors, states:

"We now know that the people who first domesticated the horse in Central Asia were the descendants of ice age hunters, who went on to become the earliest pastoralists in the region. Despite their local innovations, these peoples were overrun and replaced by European steppe pastoralists in the middle and later Bronze Age, and their horses were replaced too."

Languages spread through exchanges between several cultures
The authors also demonstrate the oldest known Indo-European language, Hittite, did not result from a massive population migration from the Eurasian Steppe as previously claimed.

In contrast to a series of recent studies on population movement in Europe during the Bronze Age, the new results from Asia suggest that population and language spread across the region is better understood by groups of people mixing together.

Gojko Barjamovic, Senior Lecturer on Assyriology at Harvard University, explains:

"In Anatolia, and parts of Central Asia, which held densely settled complex urban societies, the history of language spread and genetic ancestry is better described in terms of contact and absorption than by simply a movement of population."

He adds:

"The Indo-European languages are usually said to emerge in Anatolia in the 2nd millennium BCE. However, we use evidence from the palatial archives of the ancient city of Ebla in Syria to argue that Indo-European was already spoken in modern-day Turkey in the 25th century BCE. This means that the speakers of these language must have arrived there prior to any Yamnaya expansions."

The study also shows that the spread of the Indo-Iranian languages to South Asia, with Hindi, Urdu and Persian as major modern offshoots, cannot result from the Yamnaya expansions. Rather, the Indo-Iranian languages spread with a later push of pastoralist groups from the South Ural Mountains during the Middle to Late Bronze Age.

Prior to entering South Asia, these groups, thought to have spoken an Indo-Iranian language, were impacted by groups with an ancestry typical of more western Eurasian populations. This suggests that the Indo-Iranian speakers did not split off from the Yamnaya population directly, but were more closely related to the Indo-European speakers that lived in Eastern Europe.

Unique collaboration between the humanities and the natural sciences
In this study, geneticists, historians, archaeologists and linguists find common ground - pointing to increased interaction between the steppe and the Indus Valley during the Late Bronze Age as the most plausible time of entry of Indo-European languages in South Asia. Several authors of the paper had radically conflicting views before the final interpretation was achieved.

Lead author on the article, Peter de Barros Damgaard, who is a geneticist working at the University of Copenhagen comments:

"The project has been an extremely enriching and exciting process. We were able to direct many very different academic fields towards a single coherent approach. By asking the right questions, and keeping limitations of the data in mind, contextualizing, nuancing, and keeping dialogues open between scholars of radically different backgrounds and approaches, we have carved out a path for a new field of research. We have already seen too many papers come out in which models produced by geneticists working on their own have been are accepted without vital input from other fields, and, at the other extreme, seen archaeologists opposing new studies built on archaeogenetic data, due to a lack of transparency between the fields.

"Data on ancient DNA is astonishing for its ability to provide a fine-grained image of early human mobility, but it does stand on the shoulders of decades of work by scholars in other fields, from the time of excavation of human skeletons to interpreting the cultural, linguistic origins of the samples. This is how cold statistics are turned into history."

Guus Kroonen adds:

"The recent breakthrough in ancient genomics poses challenges for archaeologists, linguists and historians because old hypotheses on the spread of languages and cultures can now be tested against a whole new line of evidence on prehistoric mobility. As a result, we now see that geneticists are driven by key questions from the humanities, and that research within the humanities is energized by the influx of new data from the sciences. In the future, we hope to see more cross-disciplinary co-operations, such as the one leading to this study."