Monday, February 27, 2017

38,000-year-old engravings confirm ancient origins of pointillist technique used by Seurat, Van Gogh

Newly discovered limestone slab from Abri Cellier with pointillist mammoth in profile view formed my dozens of individual punctuations and re-shaping of the natural edge of the block to conform to the animals head and back line.
Photo and drawing by R. Bourrillon.
A newly discovered trove of 16 engraved and otherwise modified limestone blocks, created 38,000 years ago, confirms the ancient origins of the pointillist techniques later adopted by 19th and 20th century artists such as Georges Seurat, Vincent Van Gogh, Camille Pissarro, and Roy Lichtenstein.

"We're quite familiar with the techniques of these modern artists," observes New York University anthropologist Randall White, who led the excavation in France's Vézère Valley. "But now we can confirm this form of image-making was already being practiced by Europe's earliest human culture, the Aurignacian."

Pointillism, a painting technique in which small dots are used to create the illusion of a larger image, was developed in the 1880s. However, archaeologists have now found evidence of this technique thousands of years earlier -- dating back more than 35,000 years.

The findings appear in the journal Quaternary International.

Major discoveries by White and his colleagues--which include images of mammoths and horses--confirm that a form of pointillism was used by the Aurignacian, the earliest modern human culture in Europe. These add weight to previous isolated discoveries, such as a rhinoceros, from the Grotte Chauvet in France, formed by the application of dozens of dots, first painted on the palm of the hand, and then transferred to the cave wall.

Earlier this year, White's team reported the uncovering of a 38,000-year-old pointillist image of an aurochs or wild cow--a finding that marks some of the earliest known graphic imagery found in Western Eurasia and offers insights into the nature of modern humans during this period. Now, in short order they have found another pointillist image--this time of a woolly mammoth--in a rock shelter of the same period known as Abri Cellier located near the previous find-site of Abri Blanchard.

Abri Cellier has long been on archeologists' short-list of major art-bearing sites attributed to the European Aurignacian. Excavations in 1927 yielded 15 engraved and/or pierced limestone blocks that have served as a key point of reference for the study of Aurignacian art in the region.

In 2014, White and his colleagues returned to Cellier, seeking intact deposits that would allow a better understanding of the archaeological sequence at the site and its relationship to other Aurignacian sites. They had their fingers crossed that the new excavation might yield new engraved images in context, but nothing prepared them for the discovery of the 16 stone blocks detailed in the Quaternary International article. One of these, broken in half prehistorically, was found in place with a radiocarbon date of 38,000 years ago.

Remarkably, the remaining 15 blocks, including the pointillist mammoth, one of three mammoth figures recognized during the new work at Cellier, had been left on-site by the 1927 excavators. As many of the engraved traces are rudimentary and thus difficult to interpret, the original excavators set them aside just in case they might have something inscribed on them. The new article presents evidence that the 38,000 year date for the newly excavated engraving also applies to the new trove and to the other blocks found in 1927 and now housed in the French National Prehistory Museum.

Study shows ancient humans arrived in South America in multiple waves

Analysis of ancient human skulls found in southeastern Brazil are providing new insights into the complex narrative of human migration from our origins in sub-Saharan Africa to the peopling of the Americas tens of thousands of years later.

The many differences in cranial morphology, the study of skull shape, seen in Paleoamerican remains found in the Lagoa Santa region of Brazil suggest a model of human history that included multiple waves of population dispersals from Asia, across the Bering Strait, down the North American coast and into South America.

The findings published Wednesday (Feb. 22, 2017) in the journal Science Advances suggest that Paleoamericans share a last common ancestor with modern native South Americans outside, rather than inside, the Americas and underscore the importance of looking at both genetic and morphological evidence, each revealing different aspects of the human story, to help unravel our species' history.

"When you look at contemporary genomic data, the suggestion, particularly for South America, was for one wave of migration and that indigenous South American people are all descendants of that wave," says Noreen von Cramon-Taubadel, an associate professor of anthropology at the University at Buffalo and the paper's lead author. "But our data is suggesting that there were at least two, if not more, waves of people entering South America."

How people settled the Americas is a debate that has continued for years in the scientific community. It's now clear that the first human entry into the Americas began at least 15,000 years ago and dispersed quickly into South America following a coastal Pacific route.

The conundrum of conflicting data between morphology and genetics is among the issues fueling the debate of how people first entered the New World, but von Cramon-Taubadel's conclusions are similar to previous morphological research while also relying on a pioneering method to reach those conclusions.

"We've adopted and modified the method from ecology, but to my knowledge this method has never been used in an anthropological setting before," she says.

In the past, researchers have looked mainly at the overall similarities between the morphology of prehistoric skeletons from the Americas compared with the morphology of living people. Models of dispersal, each with a different number of waves that attempt to match existing data, have also been used.

But von Cramon-Taubadel's current research with Mark Hubbe, an associate professor in the Department of Anthropology at Ohio State University, and University of Tübingen researcher André Strauss, doesn't make any previous assumptions about dispersals. It looks at an existing population as descendants of many possible branches of a theoretical tree of relatedness and then uses statistics to determine where in the tree their sample best fits.

This method has the advantage of not needing pre-determined models of dispersal but rather considers all possible patterns of relatedness.

All living people, von Cramon-Taubadel explains, have a common ancestor, but not all fossils necessarily contribute to the ancestry of living people. Some populations of modern humans did not survive or made only a marginal contribution to living people. So fossils of these extinct humans provide few clues about the ancestry of living people.

"There are other fossils, particularly in the Americas and Eurasia where at the moment we are not 100 percent sure how they fit into the human picture," von Cramon-Taubadel says. "We could use this method to elucidate where they sit and to what extent those populations actually play a role in the modern ancestry of people in those areas."

Puzzle of the Maya pendant

To say that UC San Diego archaeologist Geoffrey Braswell was surprised to discover a precious jewel in Nim Li Punit in southern Belize is something of an understatement.

The jade once belonging to an ancient Maya king is inscribed with 30 hieroglyphs. It was used during important religious ceremonies.
Courtesy G. Braswell/UC San Diego

"It was like finding the Hope Diamond in Peoria instead of New York," said Braswell, who led the dig that uncovered a large piece of carved jade once belonging to an ancient Maya king. "We would expect something like it in one of the big cities of the Maya world. Instead, here it was, far from the center," he said.

The jewel -- a jade pendant worn on a king's chest during key religious ceremonies -- was first unearthed in 2015. It is now housed at the Central Bank of Belize, along with other national treasures. Braswell recently published a paper in the Cambridge University journal Ancient Mesoamerica detailing the jewel's significance. A second paper, in the Journal of Field Archaeology, describes the excavations.

The pendant is remarkable for being the second largest Maya jade found in Belize to date, said Braswell, a professor in the Department of Anthropology at UC San Diego. The pendant measures 7.4 inches wide, 4.1 inches high and just 0.3 inches thick. Sawing it into this thin, flat form with string, fat and jade dust would have been a technical feat. But what makes the pendant even more remarkable, Braswell said, is that it's the only one known to be inscribed with a historical text. Carved into the pendant's back are 30 hieroglyphs about its first owner.

"It literally speaks to us," Braswell said. "The story it tells is a short but important one." He believes it may even change what we know about the Maya.

Also important: The pendant was "not torn out of history by looters," said Braswell. "To find it on a legal expedition, in context, gives us information about the site and the jewel that we couldn't have otherwise had or maybe even imagined."

Where the jewel was found

Nim Li Punit is a small site in the Toledo District of Belize. It sits on a ridge in the Maya Mountains, near the contemporary village of Indian Creek. Eight different types of parrot fly overhead. It rains nine months of the year.

On the southeastern edge of the ancient Maya zone (more than 250 miles south of Chichen Itza in Mexico, where similar but smaller breast pieces have been found), Nim Li Punit is estimated to have been inhabited between A.D. 150 and 850. The site's name means "big hat." It was dubbed that, after its rediscovery in 1976, for the elaborate headdress sported by one of its stone figures. Its ancient name might be Wakam or Kawam, but this is not certain.

Braswell, UC San Diego graduate students Maya Azarova and Mario Borrero, along with a crew of local people, were excavating a palace built around the year 400 when they found a collapsed, but intact, tomb. Inside the tomb, which dates to about A.D. 800, were 25 pottery vessels, a large stone that had been flaked into the shape of a deity and the precious jade pectoral. Except for a couple of teeth, there were no human remains.

What was it doing there?

The pendant is in the shape of a T. Its front is carved with a T also. This is the Mayan glyph "ik'," which stands for "wind and breath." It was buried, Braswell said, in a curious, T-shaped platform. And one of the pots discovered with it, a vessel with a beaked face, probably depicts a Maya god of wind.

Wind was seen as vital by the Maya. It brought annual monsoon rains that made the crops grow. And Maya kings -- as divine rulers responsible for the weather -- performed rituals according to their sacred calendar, burning and scattering incense to bring on the wind and life-giving rains. According to the inscription on its back, Braswell said, the pendant was first used in A.D. 672 in just such a ritual.

Two relief sculptures on large rock slabs at Nim Li Punit also corroborate that use. In both sculptures, a king is shown wearing the T-shaped pendant while scattering incense, in A.D. 721 and 731, some 50 and 60 years after the pendant was first worn.

By the year 800, the pendant was buried, not with its human owner, it seems, but just with other objects. Why? The pendant wasn't a bauble, Braswell said, "it had immense power and magic." Could it have been buried as a dedication to the wind god? That's Braswell's educated hunch.

Maya kingdoms were collapsing throughout Belize and Guatemala around A.D. 800, Braswell said. Population levels plummeted. Within a generation of the construction of the tomb, Nim Li Punit itself was abandoned.

"A recent theory is that climate change caused droughts that led to the widespread failure of agriculture and the collapse of Maya civilization," Braswell said. "The dedication of this tomb at that time of crisis to the wind god who brings the annual rains lends support to this theory, and should remind us all about the danger of climate change."

Still and again: What was it doing there?

The inscription on the back of the pendant is perhaps the most intriguing thing about it, Braswell said. The text is still being analyzed by Braswell's coauthor on the Ancient Mesoamerica paper, Christian Prager of the University of Bonn. And Mayan script itself is not yet fully deciphered or agreed upon.

But Prager and Braswell's interpretation of the text so far is this: The jewel was made for the king Janaab' Ohl K'inich. In addition to noting the pendant's first use in A.D. 672 for an incense-scattering ceremony, the hieroglyphs describe the king's parentage. His mother, the text implies, was from Cahal Pech, a distant site in western Belize. The king's father died before aged 20 and may have come from somewhere in Guatemala.

It also describes the accession rites of the king in A.D. 647, Braswell said, and ends with a passage that possibly links the king to the powerful and immense Maya city of Caracol, located in modern-day Belize.

"It tells a political story far from Nim Li Punit," Braswell said. He notes that Cahal Pech, the mother's birthplace, for example, is 60 miles away. That's a five-hour bus ride today, and back then would have been many days' walk -- through rainforest and across mountains. How did the pendant come to this outpost?

While it's possible it had been stolen from an important place and whisked away to the provinces, Braswell doesn't think so. He believes the pendant is telling us about the arrival of royalty at Nim Li Punit, the founding of a new dynasty. The writing on the pendant is not particularly old by Maya standards, but it's the oldest found at Nim Li Punit so far, Braswell said. It's also only after the pendant's arrival that other hieroglyphs and images of royalty begin to show up on the site's stelae, or sculptured stone slabs.

It could be that king Janaab' Ohl K'inich himself moved to Nim Li Punit, Braswell said. Or it could be that a great Maya state was trying to ally with the provinces, expand its power or curry favor by presenting a local king with the jewel. Either way, Braswell believes, the writing on the pendant indicates ties that had been previously unknown.

"We didn't think we'd find royal, political connections to the north and the west of Nim Li Punit," said Braswell, who has been excavating in Belize since 2001 and at Nim Li Punit since 2010. "We thought if there were any at all that they'd be to the south and east."

Even if you ignore the writing and its apparent royal provenance, the jade stone itself is from the mountains of Guatemala, southwest of Belize. There are few earlier indications of trade in that direction either, Braswell said.

We may never know exactly why the pendant came to Nim Li Punit or why it was buried as it was, but Braswell's project to understand the site continues. He plans to return in the spring of 2017. This time, he also wants to see if he might discover a tie to the Caribbean Sea. After all, that's a mere 12 miles downriver, a four-hour trip by canoe.

1,800 Year Old Hebrew Inscriptions were Exposed on a Column Capital in Peqiin Village

Margalit Zinati of Peqi?in village, resting on the ancient stone. Photo: Ritvo, courtesy of Beit Zinati

An 1,800 year old limestone capital dating to the Roman period that is engraved with two Hebrew inscriptions was discovered during the course of restoration and conservation work being carried out in the ancient synagogue and neighboring Beit Zinati visitor center at Peqiin, in the Western Galilee. The work is being conducted by the Council for Conservation of Heritage Sites in Israel as part of a heritage project by the Ministry of Jerusalem Affairs and Heritage. The stone was found upside down in the building’s courtyard, and upon discovery of the inscriptions archaeologists of the Israel Antiquities Authority arrived at the site in order to examine the special find. A preliminary analysis of the engraving suggests that these are dedicatory inscriptions honoring donors to the synagogue.

According to Yoav Lerer, the IAA inspector in the Western Galilee, “The Talmudic and Midrashic sources tell of the Galilean sages that lived in Peqiin, including Rabbi Shimon Bar Yochai, who hid from the Romans in a cave. However, there are those who disagree with the identification of the location of Peqi?in. I believe that these inscriptions will add an important tier to our knowledge about the Jewish settlement in the village of Peqiiin during the Roman and Byzantine periods”.

In the past year rehabilitation and conservation work was carried out in Peqiin’s ancient synagogue and nearby Beit Zinati in order to upgrade the visitor center located there. The visitor center will tell the two thousand year long history of the Jews in the village, and the unique story of the Zinati family – the village’s oldest Jewish family. Until today Margalit Zinati, the last member of the Jewish Zinati family to "keep the flame alive", resides in the house next door to the synagogue.

Ze’ev Elkin, the Minister of Jerusalem Affairs and Heritage, said "Peqiin is one of the most significant sites in the Galilee, and is a place where there has always been a Jewish presence. It is a great honor for me that during my tenure in office such an important discovery has been made that tells this 2,000 year old story of the Land of Israel”.

Uriel Rosenboym, director of Beit Zinati says with great excitement “This is a historical discovery of unparalleled importance that confirms what the late President Yitzhak Ben Zvi maintained in the early twentieth century about the Jewish settlement at Peqiin. No one can argue with the written artifact. There was an ancient synagogue here and the synagogue was built in its current form in recent centuries. We thank the Ministry of Jerusalem Affairs and Heritage, which aims to preserve the heritage of Peqiin’s Jews. We are pleased to open the new museum with a historic message about this ancient community. Although the stone itself was taken to be studied by the Israel Antiquities Authority, this unique story of the keepers of the flame in Peqiin is revealed in the renewed museum”.

Discovery of Rare Bronze Age Weapon Hoard

GUARD Archaeologists have recently recovered a very rare and internationally significant hoard of metalwork that is a major addition to Scottish Late Bronze Age archaeology.

A bronze spearhead decorated with gold was found alongside a bronze sword, pin and scabbard fittings in a pit close to a Bronze Age settlement excavated by a team of GUARD Archaeologists led by Alan Hunter Blair, on behalf of Angus Council in advance of their development of two football pitches at Carnoustie.

Each individual object in the hoard is significant but the presence of gold ornament on the spearhead makes this an exceptional group. Within Britain and Ireland, only a handful of such spearheads are known - among them a weapon hoard found in 1963 at Pyotdykes Farm to the west of Dundee. These two weapon hoards from Angus - found only a few kilometres apart - hint at the wealth of the local warrior society during the centuries around 1000-800 BC.

There are two more aspects that elevate the Carnoustie discovery to international significance. The first aspect is the extremely rare survival of organic remains. A leather and wooden scabbard encased the Carnoustie sword and is probably the best preserved Late Bronze Age sword scabbard ever found in Britain. Fur skin survives around the spearhead, and textile around the pin and scabbard. Such organic remains rarely survive on dryland sites.

The second aspect is that the hoard is not an isolated find but was buried within a Late Bronze Age settlement, which means that once the excavation has been completed it will be possible to study the archaeological context of the hoard, revealing new insights into the local Bronze Age community that buried it. Not least of which was the longevity of settlement here. For the excavation has also revealed the largest Neolithic hall so far found in Scotland, a building dating to around 4000 BC and that may have been as old to the people who buried the weapon hoard, as they are to us.

‘It is very unusual to recover such artefacts in a modern archaeological excavation, which can reveal so much about the context of its burial. Owing to the fragile nature of these remains when we first discovered them, our team removed the entire pit, and the surrounding subsoil which it was cut into, as a single 80 kg block of soil,' said GUARD Project Officer Alan Hunter Blair. 'This was then delivered to our Finds Lab where it was assessed by a specialist Finds Conservator to plan how it could be carefully excavated and the artefacts conserved.’

'Organic evidence like Bronze Age wooden scabbards rarely survive so this just underlines how extraordinary these finds are,' said GUARD Project Officer, Beth Spence, who undertook the excavation of the hoard in GUARD Archaeology’s Finds Lab along with Conservator Will Murray from the Scottish Conservation Studio.

Along with the hoard, the GUARD Archaeology team have discovered around 1000 archaeological features, among them the remains of up to 12 sub-circular houses that probably date to the Bronze Age along with the remains of 2 rectilinear halls that likely date to the Neolithic period. Some of the other archaeology on site consists of clusters of large pits containing discarded, broken pots and lithic artefacts. It is unclear yet if the archaeological remains comprise a settlement that lasted from the Neolithic until the Late Bronze Age or if it comprises several settlements built upon the same site but separated in time by many centuries.

Claire Herbert of ACAS, Archaeological advisers to Angus Council, said ‘The archaeology uncovered at Carnoustie is undoubtedly of national and international significance, and will certainly further enhance our knowledge of the prehistory of this area, providing an invaluable opportunity to learn more about how people in Angus lived in the Neolithic and Bronze Age.’

Angus Council communities convener Donald Morrison added: ‘It is clear that Carnoustie was as much a hive of activity in Neolithic and Bronze Age times as it is now. The discoveries made on land destined for sporting development have given us a fascinating insight into our Angus forebears and I look forward to learning more about our local prehistory.’

Vice convener Jeanette Gaul said: ‘To make such a find while preparing to create sports facilities for Carnoustie came as a huge surprise to us all. We’ve since learned it is of national and, indeed, international importance. But I am pleased that the archaeologists have involved local young people in the excavation project and are offering us all an insight into Angus’ distant past.’

Thursday, February 23, 2017

Neanderthal DNA contributes to human gene expression


This visual abstract depicts the findings of McCoy et al., who show genome-wide interrogation of the functional differences between modern human and Neanderthal alleles reveals that Neanderthal-inherited sequences are not silent remnants of ancient interbreeding but have a measurable impact on gene expression that may contribute to phenotypic variation in modern humans.
McCoy et al./Cell 2017

The last Neanderthal died 40,000 years ago, but much of their genome lives on, in bits and pieces, through modern humans. The impact of Neanderthals' genetic contribution has been uncertain: Do these snippets affect our genome's function, or are they just silent passengers along for the ride? In Cell on February 23, researchers report evidence that Neanderthal DNA sequences still influence how genes are turned on or off in modern humans. Neanderthal genes' effects on gene expression likely contribute to traits such as height and susceptibility to schizophrenia or lupus, the researchers found.

"Even 50,000 years after the last human-Neanderthal mating, we can still see measurable impacts on gene expression," says geneticist and study co-author Joshua Akey of the University of Washington School of Medicine. "And those variations in gene expression contribute to human phenotypic variation and disease susceptibility."

Previous studies have found correlations between Neanderthal genes and traits such as fat metabolism, depression, and lupus risk. However, figuring out the mechanism behind the correlations has proved difficult. DNA can be extracted from fossils and sequenced, but RNA cannot. Without this source of information, scientists can't be sure exactly if Neanderthal genes functioned differently than their modern human counterparts. They can, however, look to gene expression in modern humans who possess Neanderthal ancestry.

In this study, researchers analyzed RNA sequences in a dataset called the Genotype-Tissue Expression (GTEx) Project, looking for people who carried both Neanderthal and modern human versions of any given gene--one version from each parent. For each such gene, the investigators then compared expression of the two alleles head-to-head in 52 different tissues.

"We find that for about 25% of all those sites that we tested, we can detect a difference in expression between the Neanderthal allele and the modern human allele," says the study's first author, UW postdoctoral researcher Rajiv McCoy.

Expression of Neanderthal alleles tended to be especially low in the brain and the testes, suggesting that those tissues may have experienced more rapid evolution since we diverged from Neanderthals approximately 700,000 years ago. "We can infer that maybe the greatest differences in gene regulation exist in the brain and testes between modern humans and Neanderthals," says Akey.

One example uncovered by this study is a Neanderthal allele of a gene called ADAMTSL3 that decreases risk of schizophrenia, while also influencing height. "Previous work by others had already suggested that this allele affects alternative splicing. Our results support this molecular model, while also revealing that the causal mutation was inherited from Neanderthals," says McCoy. Alternative splicing refers to a process in which mRNAs are modified before they leave the cell's nucleus. When the Neanderthal mutation is present, the cell's machinery removes a segment of the mRNA that is expressed in the modern human version. The cell ends up making a modified protein because of a single mutation from a Neanderthal ancestor.

The connection between that modified protein, height, and schizophrenia still requires more investigation, but it's an example of how small differences between modern humans and Neanderthals can contribute to variation in people.

"Hybridization between modern humans and Neanderthals increased genomic complexity," explains Akey. "Hybridization wasn't just something that happened 50,000 years ago that we don't have to worry about anymore. Those little bits and pieces, our Neanderthal relics, are influencing gene expression in pervasive and important ways."

Next steps may include investigating whether Denisovans--another species of hominins that crossbred with modern humans--are contributing to gene expression, as well as applying the side-by-side method of expression analysis more broadly. For this study, McCoy and his colleagues had to develop a new statistical approach to sift through the immense amount of RNA data, but the same technique could be used to compare gene expression differences between modern human alleles.

Tuesday, February 21, 2017

Radiocarbon dating and DNA show ancient Puebloan leadership in the maternal line

Discovering who was a leader, or even if leaders existed, from the ruins of archaeological sites is difficult, but now a team of archaeologists and biological anthropologists, using a powerful combination of radiocarbon dating and ancient DNA, have shown that a matrilineal dynasty likely ruled Pueblo Bonito in New Mexico for more than 300 years.

"We are not saying that this was a state-level society," said Douglas J. Kennett, head and professor of anthropology, Penn State. "But we don't think it was egalitarian either."

Archaeologists have described the Chaco Phenomenon as anything from an egalitarian society without any rulers at all, to a full-fledged state-level society or kingdom. The researchers now think that Chaco Canyon was much more than a leaderless conglomeration of people, but a hierarchically organized society with leadership inherited through the maternal line.

Typically, the only things found in prehistoric archaeological ruins to indicate elevated status are grave goods -- the artifacts found with burials. Throughout the Southwest it is unusual to find formal burials within structures, because most people were buried with limited grave goods outside housing compounds, but in excavations sponsored by the American Museum of Natural History and carried out in the 1890s at Chaco Canyon, archaeologists found room 33 in Pueblo Bonito -- a burial crypt within a 650-room pueblo dating between 800 and 1130 -- that contained 14 burials.

"It has been clear for some time that these were venerated individuals, based on the exceptional treatment they received in the afterlife -- most Chacoans were buried outside of the settlement and never with such high quantities of exotic goods," said Adam Watson, postdoctoral fellow in the American Museum of Natural History Division of Anthropology. "But previously one could only speculate about the exact nature of their relationship to one another."

The researchers note in today's (Feb. 21) issue of Nature Communications, that this 6.5 by 6.5 foot room "was purposely constructed as a crypt for a high-status member of this nascent community and ultimately his lineal descendants." The initial burial was of a male in his 40s who died from a lethal blow to the head. He was buried with more than 11,000 turquoise beads, 3,300 shell beads and other artifacts including abalone shells and a conch shell trumpet originating from the Pacific Ocean and Gulf of California far from central New Mexico. This burial is the richest ever found in the American Southwest.

Another individual was buried above this initial interment and a split plank floor placed above them. In the space above, another 12 burials took place over the span of 300 years.

"We originally worked with Steve Plog (David A. Harrison Professor of Archaeology, University of Virginia) to radiocarbon date these burials," said Kennett. "The results of this work had all the Individuals dating to a 300 year period. Then the question came up, are they related?"

Kennett and Plog teamed up with George Perry, assistant professor of anthropology and biology, Penn State and Richard George, a graduate student in anthropology, to first examine the mitochondrial genomes of these individuals."

When the results came back, the researchers found that all the individuals shared the same mitochondrial genome sequence. Mitochondrial DNA (mtDNA) is inherited only from an individual's mother, so matching mtDNA indicates that not only where all the individuals from the same family, but the inheritance was matrilineal -- through the mother.

"First we thought this could be some kind of contamination problem," said Kennett. "We checked for contamination, but found no evidence for it and David Reich's laboratory at Harvard Medical School corroborated our results."

Working with Reich, professor of genetics, the researchers then wondered if they could determine specific relationships among these individuals.

"Using DNA sequences from the nuclear genome combined with the radiocarbon dates, we identified a mother-daughter pair and a grandmother-grandson relationship," said Kennett.

"For the first time, we're saying that one kinship group controlled Pueblo Bonito for more than 300 years," said Plog "This is the best evidence of a social hierarchy in the ancient Southwest."

Genetic data show mainly men migrated from the Pontic steppe to Europe 5,000 years ago

A new study, looking at the sex-specifically inherited X chromosome of prehistoric human remains, shows that hardly any women took part in the extensive migration from the Pontic-Caspian Steppe approximately 5,000 years ago. The great migration that brought farming practices to Europe 4,000 years earlier, on the other hand, consisted of both women and men. The difference in sex bias suggests that different social and cultural processes drove the two migrations.

Genetic data suggest that modern European ancestry represents a mosaic of ancestral contributions from multiple waves of prehistoric migration events. Recent studies of genomic variation in prehistoric human remains have demonstrated that two mass migration events are particularly important to understanding European prehistory: the Neolithic spread of agriculture from Anatolia starting around 9,000 years ago, and migration from the Pontic-Caspian Steppe around 5,000 years ago. These migrations are coincident with large social, cultural, and linguistic changes, and each has been inferred to have replaced more than half of the contemporaneous gene pool of resident Central Europeans.

Dramatic events in human prehistory can be investigated using patterns of genetic variation among the people that lived in those times. In particular, studies of differing female and male demographic histories on the basis of ancient genomes can provide information about complexities of social structures and cultural interactions in prehistoric populations.

Researchers from Uppsala and Stanford University investigated the genetic ancestry on the sex-specifically inherited X chromosome and the autosomes in 20 early Neolithic and 16 Late Neolithic/Bronze Age human remains. Contrary to previous hypotheses suggesting patrilocality (social system in which a family resides near the man's parents) of many agricultural populations, they found no evidence of sex-biased admixture during the migration that spread farming across Europe during the early Neolithic.

For later migrations from the Pontic steppe during the early Bronze Age, however, we find a dramatic male bias. There are simply too few X-chromosomes from the migrants, which points to around ten migrating males for every migrating female, says Mattias Jakobsson, professor of Genetics at the Department of Organismal Biology, Uppsala University.

The research group found evidence of ongoing, primarily male, migration from the steppe to central Europe over a period of multiple generations, with a level of sex bias that excludes a pulse migration during a single generation.

The contrasting patterns of sex-specific migration during these two migrations suggest a view of differing cultural histories in which the Neolithic transition was driven by mass migration of both males and females in roughly equal numbers -- perhaps whole families -- whereas the later Bronze Age migration and cultural shift were instead driven by male migration.

Scarcity of resources led to violence in prehistoric central California

There are two views related to the origins of violence and warfare in humans -- one view that humans in earlier times were peaceful and lived in harmony and a second view that there has always been competition for resources, war and violence.

The second view was confirmed in Professor Mark Allen's study, titled "Resource scarcity drives lethal aggression among prehistoric hunter-gathers in central California,"published in the Proceedings of the National Academy of Sciences of the United States of America.

Using an archeological database of human burials of remains from thousands of Central California inhabitants between going back more than 1,000 years, Allen and his fellow researchers looked at the wound marks from physical traumas they suffered. They also compared that evidence to the environment and looked at the way the communities were socially organized, he says.

They found that California had the highest population density in all of North America, with lots of small groups living in close proximity. There were approximately 100 different languages spoken in California at the time. The data showed how the scarcity of resources and violence correlates.
"When people are stressed out and worried about protecting the group, they are willing to be aggressive," he says. "Violence is about resources for the group."

The data related to the remains showed that about 7 percent of the population at that time had evidence of forced traumas, whether they were shot by an arrow, stabbed or bludgeoned. For females it was 5 percent and for males it was 11 percent, a percentage of violent trauma not even reached during World War II, Allen says.

Wednesday, February 15, 2017

Looking at Sardinian DNA for genetic clues to an island's -- and Europe's -- past

Sardinia sits at a crossroads in the Mediterranean Sea, the second largest island next to Sicily. Surrounded by sparkling turquoise waters, this Mediterranean jewel lies northwest of the toe of the Italian peninsula boot, about 350 kilometers due west of Rome. 
For evolutionary biologists, islands are often intriguing, geographically isolated pockets with unique populations that can be ripe for exploration. 
Now, in a new study appearing in the advanced online edition of Molecular Biology and Evolution an international team led by geneticist Anna Olivieri from the University of Pavia tackles a highly interesting question: what were the origins of the Sardinian population in the context of European prehistory and ancient human migrations? 
The authors analyzed 3,491 modern, whole mitochondrial DNA genomes from Sardinia (which are only passed down maternally). These were compared with 21 samples of ancient mitogenomes from the island, a large panel of non-Sardinian mitogenomes ---and even Ötzi (the nickname of Europe's oldest natural mummy, the 3,300 BCE-year old "Tyrolean Iceman") ---to better understand their origins. 
Their findings show Sardinia as an outlier in the general European genetic landscape. Almost 80 percent of modern Sardinian mitogenomes belong to branches that cannot be found anywhere else outside the island. Thus, they were defined as Sardinian-Specific Haplogroups (SSHs) that most likely arose in the island after its initial occupation. Almost all SSHs coalesce in the post-Nuragic, Nuragic and Neolithic-Copper Age periods. However, some rare SSHs display age estimates older than 7,800 years ago, the postulated archeologically-based starting time of the Neolithic in Sardinia. 
"Our analyses raise the possibility that several SSHs may have already been present on the island prior to the Neolithic," said prof. Francesco Cucca, from the Institute of Genetic and Biomedical Research (IRGB), at the CNR in Cagliari (Sardinia). 
The most plausible candidates would include haplogroups K1a2d and U5b1i1, which together comprise almost 3 percent of modern Sardinians, and possibly others. Such a scenario would not only support archaeological evidence of a Mesolithic occupation of Sardinia, but could also suggest a dual ancestral origin of its first inhabitants. K1a2d is of Late Paleolithic Near Eastern ancestry, whereas U5b1i1 harbours deep ancestral roots in Paleolithic Western Europe.
This work provides evidence that contemporary Sardinians harbour a unique genetic heritage, as a result of their distinct history and relative isolation from the demographic upheavals of continental Europe. Anna Olivieri stresses: "It now seems plausible that human mobility, inter-communication and gene flow around the Mediterranean from Late Glacial times onwards may well have left signatures that survive to this day. Some of these signals are still retained in modern Sardinians." 
"Although in the past the stress has often been on the spread of the Neolithic, genetic studies too are beginning to emphasize the complexity and mosaic nature of human ancestry in the Mediterranean, and indeed in Europe more widely," concludes prof. Antonio Torroni, from the University of Pavia. "Future work on ancient DNA should be able to test directly to what extent this more complex model is supported by genetic evidence, and whether our predictions of Mesolithic ancestry in contemporary Sardinians can be sustained."

Tuesday, February 14, 2017

Corn cultivation and nderstanding how and why Cahokia arose

A new study contradicts decades of thought, research and teaching on the history of corn cultivation in the American Bottom, a floodplain of the Mississippi River in Illinois. The study refutes the notion that Indian corn, or maize, was cultivated in this region hundreds of years before its widespread adoption at about 1000 A.D.

The findings, reported in the journal American Antiquity, are important in understanding how and why Cahokia, the first major metropolitan center in North America, arose, said Thomas Emerson, the director of the Illinois State Archaeological Survey at the University of Illinois, where the new study was conducted.

Cahokia was a vast, highly organized settlement with tens of thousands of inhabitants in its heyday, Emerson said. Its dramatic rise near present-day St. Louis and East St. Louis, Illinois, at about A.D. 950 and its sudden demise by 1350 have long been a source of fascination.

There is broad agreement that corn was cultivated in this region at about 1000 and widely consumed by the people of this time period, Emerson said. Corn fragments, including cobs and kernels, show up in sites dating to 1000 or later. Skeletal analyses from bodies buried at Cahokia also reveal the devastating impact of corn on people's teeth. These signs, as well as chemical signatures of corn consumption in the teeth and bone, also date to 1000 and after, he said.

The new findings challenge earlier reports that maize was cultivated and consumed in the American Bottom as early as 60 years B.C.

The early conclusions - in studies conducted before 2000 - were based on flawed approaches to analyzing ancient materials, said Mary Simon, an archaeobotanist with ISAS who conducted the new study. Rather than dating charred plant fragments directly, researchers analyzed charcoal or other "associated materials" to determine the age of the plants, she said.

"We have since learned that a piece of charcoal or other material found adjacent to a corn kernel in an archaeological site could date to a later or earlier time period than the corn," Simon said. Also, visual identifications can be wrong, she said.

Scientists now date plant fragments directly using accelerated mass spectrometry, a technology that was just "coming into vogue in the 1990s" and used at that time to determine the age of materials, Simon said.

Today, stable isotope mass spectrometry can be used in conjunction with AMS to detect differences between plant types, information that aids in plant identification, she said. Corn and other grasses absorb atmospheric carbon differently than other plants. This is reflected in the ratio of carbon isotopes - carbon atoms with differing masses - in plant tissues, Simon said.

"The beauty of this procedure is not only do you get an absolute date, you also get that carbon isotope ratio, so you know, first, how old it is, and, second, whether or not it's corn," she said.

In the new study, Simon revisited botanical samples from Holding, an archaeological site in western Illinois that was occupied from about 150 B.C. to A.D. 300. Simon was among those who mistakenly identified plant fragments from this site as very early corn, and later AMS data confirmed its age. Those findings were published by a group of archaeologists in 1994, and were widely recognized as being the oldest directly dated corn in the eastern United States.

The new analysis, of remaining botanical samples from the Holding site, used both AMS and SIMS and found that the samples that looked like corn either were not corn or dated to A.D. 900 or later, Simon said. Researchers at Arizona State University found samples from the original study and also tested those for carbon isotope ratios. Their results confirmed that although it was old, the material dated in 1994 was not, in fact, corn.

"Basically, what we found is that myths of early corn in the central Mississippi River Valley are simply inaccurate. They've been disproved. We no longer believe that corn was at all important, that people were growing corn, that anybody was using corn to any extent at A.D. zero," Simon said. The two new studies suggest that corn was not in widespread use until 900 or later, she said.

"You can never say it wasn't present here before then," she said. "For example, there was Wyoming obsidian here at A.D. 60, so it's totally possible that a cob of corn made it here from the southwestern U.S. at an earlier date. But, until it was cultivated here, it doesn't really count."

Ancient jars found in Judea reveal earth's magnetic field is fluctuating, not diminishing

Albert Einstein considered the origin of the Earth's magnetic field one of the five most important unsolved problems in physics. The weakening of the geomagnetic field, which extends from the planet's core into outer space and was first recorded 180 years ago, has raised concern by some for the welfare of the biosphere.

But a new study published in PNAS from Tel Aviv University, Hebrew University of Jerusalem, and University of California San Diego researchers finds there is no reason for alarm: The Earth's geomagnetic field has been undulating for thousands of years. Data obtained from the analysis of well-dated Judean jar handles provide information on changes in the strength of the geomagnetic field between the 8th and 2nd centuries BCE, indicating a fluctuating field that peaked during the 8th century BCE.

"The field strength of the 8th century BCE corroborates previous observations of our group, first published in 2009, of an unusually strong field in the early Iron Age. We call it the 'Iron Age Spike,' and it is the strongest field recorded in the last 100,000 years," says Dr. Erez Ben-Yosef of TAU's Institute of Archaeology, the study's lead investigator. "This new finding puts the recent decline in the field's strength into context. Apparently, this is not a unique phenomenon -- the field has often weakened and recovered over the last millennia."

Delving into the inner structure of the planet

"We can gain a clearer picture of the planet and its inner structure by better understanding proxies like the magnetic field, which reaches more than 1,800 miles deep into the liquid part of the Earth's outer core," Dr. Ben-Yosef observes.

The new research is based on a set of 67 ancient, heat-impacted Judean ceramic storage jar handles, which bear royal stamp impressions from the 8th to 2nd century BCE, providing accurate age estimates.

"The period spanned by the jars allowed us to procure data on the Earth's magnetic field during that time -- the Iron Age through the Hellenistic Period in Judea," says Dr. Ben-Yosef. "The typology of the stamp impressions, which correspond to changes in the political entities ruling this area, provides excellent age estimates for the firing of these artifacts."

To accurately measure the geomagnetic intensity, the researchers conducted experiments at the Paleomagnetic Laboratory of Scripps Institution of Oceanography (SIO), University of California San Diego, using laboratory-built paleomagnetic ovens and a superconducting magnetometer.

"Ceramics, baked clay, burned mud bricks, copper slag -- almost anything that was heated and then cooled can become a recorder of the components of the magnetic field at the time of the event," said Dr. Ben-Yosef. "Ceramics have tiny minerals -- magnetic 'recorders' -- that save information about the magnetic field of the time the clay was in the kiln. The behavior of the magnetic field in the past can be studied by examining archaeological artifacts or geological material that were heated then cooled, such as lava."

Advanced dating method

Observed changes in the geomagnetic field can, in turn, be used as an advanced dating method complementary to the radiocarbon dating, according to Dr. Ben-Yosef. "The improved Levantine archaeomagnetic record can be used to date pottery and other heat-impacted archaeological materials whose date is unknown.

"Both archaeologists and Earth scientists benefit from this. The new data can improve geophysical models -- core-mantle interactions, cosmogenic processes and more -- as well as provide an excellent, accurate dating reference for archaeological artefacts," says Dr. Ben-Yosef.

The researchers are currently working on enhancing the archaeomagnetic database for the Levant, one of the most archaeologically-rich regions on the planet, to better understand the geomagnetic field and establish a robust dating reference.

Wednesday, February 8, 2017

Archaeologists find 12th Dead Sea Scrolls cave

Excavations in a cave on the cliffs west of Qumran, near the northwestern shore of the Dead Sea, prove that Dead Sea scrolls from the Second Temple period were hidden in the cave, and were looted by Bedouins in the middle of the last century. With the discovery of this cave, scholars now suggest that it should be numbered as Cave 12.

A piece of parchment to be processed for writing, found rolled up in a jug, in a cave on the cliffs west of Qumran excavated by Hebrew University archaeologists.
(Photo: Casey L. Olson and Oren Gutfeld)

The surprising discovery, representing a milestone in Dead Sea Scroll research, was made by Dr. Oren Gutfeld and Ahiad Ovadia from the Hebrew University of Jerusalem's Institute of Archaeology, with the collaboration of Dr. Randall Price and students from Liberty University in Virginia, USA.

The excavators are the first in over 60 years to discover a new scroll cave and to properly excavate it.

The excavation was supported by the Civil Administration of Judea and Samaria, by the Israel Nature and Parks Authority, and the Israel Antiquities Authority (IAA), and is a part of the new "Operation Scroll" launched at the IAA by its Director-General, Mr. Israel Hasson, to undertake systematic surveys and to excavate the caves in the Judean Desert.

Excavation of the cave revealed that at one time it contained Dead Sea scrolls. Numerous storage jars and lids from the Second Temple period were found hidden in niches along the walls of the cave and deep inside a long tunnel at its rear. The jars were all broken and their contents removed, and the discovery towards the end of the excavation of a pair of iron pickaxe heads from the 1950s (stored within the tunnel for later use) proves the cave was looted.

Until now, it was believed that only 11 caves had contained scrolls. With the discovery of this cave, scholars have now suggested that it would be numbered as Cave 12. Like Cave 8, in which scroll jars but no scrolls were found, this cave will receive the designation Q12 (the Q=Qumran standing in front of the number to indicate no scrolls were found).

"This exciting excavation is the closest we've come to discovering new Dead Sea scrolls in 60 years. Until now, it was accepted that Dead Sea scrolls were found only in 11 caves at Qumran, but now there is no doubt that this is the 12th cave," said Dr. Oren Gutfeld, an archaeologist at the Hebrew University's Institute of Archaeology and director of the excavation. "Finding this additional scroll cave means we can no longer be certain that the original locations (Caves 1 through 11) assigned to the Dead Sea scrolls that reached the market via the Bedouins are accurate."

Dr. Gutfeld added: "Although at the end of the day no scroll was found, and instead we 'only' found a piece of parchment rolled up in a jug that was being processed for writing, the findings indicate beyond any doubt that the cave contained scrolls that were stolen. The findings include the jars in which the scrolls and their covering were hidden, a leather strap for binding the scroll, a cloth that wrapped the scrolls, tendons and pieces of skin connecting fragments, and more."

The finds from the excavation include not only the storage jars, which held the scrolls, but also fragments of scroll wrappings, a string that tied the scrolls, and a piece of worked leather that was a part of a scroll. The finding of pottery and of numerous flint blades, arrowheads, and a decorated stamp seal made of carnelian, a semi-precious stone, also revealed that this cave was used in the Chalcolithic and the Neolithic periods.

This first excavation to take place in the northern part of the Judean Desert as part of "Operation Scroll" will open the door to further understanding the function of the caves with respect to the scrolls, with the potential of finding new scroll material. The material, when published, will provide important new evidence for scholars of the archaeology of Qumran and the Dead Sea caves.

"The important discovery of another scroll cave attests to the fact that a lot of work remains to be done in the Judean Desert and finds of huge importance are still waiting to be discovered," said Israel Hasson, Director-General of the Israel Antiquities Authority. "We are in a race against time as antiquities thieves steal heritage assets worldwide for financial gain. The State of Israel needs to mobilize and allocate the necessary resources in order to launch a historic operation, together with the public, to carry out a systematic excavation of all the caves of the Judean Desert."

Thursday, February 2, 2017

Baltic hunter-gatherers began farming without influence of migration, ancient DNA suggests

New research indicates that Baltic hunter-gatherers were not swamped by migrations of early agriculturalists from the Middle East, as was the case for the rest of central and western Europe. Instead, these people probably acquired knowledge of farming and ceramics by sharing cultures and ideas -- rather than genes -- with outside communities.

Scientists extracted ancient DNA from a number of archaeological remains discovered in Latvia and the Ukraine, which were between 5,000 and 8,000 years old. These samples spanned the Neolithic period, which was the dawn of agriculture in Europe, when people moved from a mobile hunter-gatherer lifestyle to a settled way of life based on food production.

We know through previous research that large numbers of early farmers from the Levant (the Near East) - driven by the success of their technological innovations such as crops and pottery - had expanded to the peripheral parts of Europe by the end of the Neolithic and largely replaced hunter-gatherer populations.

However, the new study, published today in the journal Current Biology, shows that the Levantine farmers did not contribute to hunter-gatherers in the Baltic as they did in Central and Western Europe.

The research team, which includes scientists from Trinity College Dublin, the University of Cambridge, and University College Dublin, says their findings instead suggest that the Baltic hunter-gatherers learned these skills through communication and cultural exchange with outsiders.

The findings feed into debates around the 'Neolithic package,' -- the cluster of technologies such as domesticated livestock, cultivated cereals and ceramics, which revolutionised human existence across Europe during the late Stone Age.

Advances in ancient DNA work have revealed that this 'package' was spread through Central and Western Europe by migration and interbreeding: the Levant and later Anatolian farmers mixing with and essentially replacing the hunter-gatherers.

But the new work suggests migration was not a 'universal driver' across Europe for this way of life. In the Baltic region, archaeology shows that the technologies of the 'package' did develop -- albeit less rapidly - even though the analyses show that the genetics of these populations remained the same as those of the hunter-gatherers throughout the Neolithic.

Andrea Manica, one of the study's senior authors from the University of Cambridge, said: "Almost all ancient DNA research up to now has suggested that technologies such as agriculture spread through people migrating and settling in new areas."

"However, in the Baltic, we find a very different picture, as there are no genetic traces of the farmers from the Levant and Anatolia who transmitted agriculture across the rest of Europe."

"The findings suggest that indigenous hunter-gatherers adopted Neolithic ways of life through trade and contact, rather than being settled by external communities. Migrations are not the only model for technology acquisition in European prehistory."

While the sequenced genomes showed no trace of the Levant farmer influence, one of the Latvian samples did reveal genetic influence from a different external source -- one that the scientists say could be a migration from the Pontic Steppe in the east. The timing (5-7,000 years ago) fits with previous research estimating the earliest Slavic languages.

Researcher Eppie Jones, from Trinity College Dublin and the University of Cambridge, was the lead author of the study. She said: "There are two major theories on the spread of Indo-European languages, the most widely spoken language family in the world. One is that they came from the Anatolia with the agriculturalists; another that they developed in the Steppes and spread at the start of the Bronze Age."

"That we see no farmer-related genetic input, yet we do find this Steppe-related component, suggests that at least the Balto-Slavic branch of the Indo-European language family originated in the Steppe grasslands of the East, which would bring later migrations of Bronze Age horse riders."

The researchers point out that the time scales seen in Baltic archaeology are also very distinct to the rest of Europe, with a much more drawn-out and piecemeal uptake of Neolithic technologies, rather than the complete 'package' that arrives with migrations to take most of Europe by storm.

Andrea Manica added: "Our evidence of genetic continuity in the Baltic, coupled with the archaeological record showing a prolonged adoption of Neolithic technologies, would suggest the existence of trade networks with farming communities largely independent of interbreeding."

"It seems the hunter-gatherers of the Baltic likely acquired bits of the Neolithic package slowly over time through a 'cultural diffusion' of communication and trade, as there is no sign of the migratory wave that brought farming to the rest of Europe during this time.

"The Baltic hunter-gatherer genome remains remarkably untouched until the great migrations of the Bronze Age sweep in from the East."

About the study

The researchers analysed eight ancient genomes - six from Latvia and two from Ukraine - that spanned a timeframe of three and a half thousand years (between 8,300 and 4,800 years ago). This enabled them to start plotting the genetic history of Baltic inhabitants during the Neolithic.

DNA was extracted from the petrous area of skulls that had been recovered by archaeologists from some of the region's richest Stone Age cemeteries. The petrous, at the base of the skull, is one of the densest bones in the body, and a prime location for DNA that has suffered the least contamination over millennia.

Wednesday, February 1, 2017

Ancient DNA reveals 'continuity' between Stone Age and modern populations in East Asia

Researchers working on ancient DNA extracted from human remains interred almost 8,000 years ago in a cave in the Russian Far East have found that the genetic makeup of certain modern East Asian populations closely resemble that of their hunter-gatherer ancestors.

The study, published today in the journal Science Advances, is the first to obtain nuclear genome data from ancient mainland East Asia and compare the results to modern populations.

The findings indicate that there was no major migratory interruption, or "population turnover", for well over seven millennia. Consequently, some contemporary ethnic groups share a remarkable genetic similarity to Stone Age hunters that once roamed the same region.

The high "genetic continuity" in East Asia is in stark contrast to most of Western Europe, where sustained migrations of early farmers from the Levant overwhelmed hunter-gatherer populations. This was followed by a wave of horse riders from Central Asia during the Bronze Age. These events were likely driven by the success of emerging technologies such as agriculture and metallurgy

The new research shows that, at least for part of East Asia, the story differs - with little genetic disruption in populations since the early Neolithic period.

Despite being separated by a vast expanse of history, this has allowed an exceptional genetic proximity between the Ulchi people of the Amur Basin, near where Russia borders China and North Korea, and the ancient hunter-gatherers laid to rest in a cave close to the Ulchi's native land.

The researchers suggest that the sheer scale of East Asia and dramatic variations in its climate may have prevented the sweeping influence of Neolithic agriculture and the accompanying migrations that replaced hunter-gatherers across much of Europe. They note that the Ulchi retained their hunter-fisher-gatherer lifestyle until recent times.

"Genetically speaking, the populations across northern East Asia have changed very little for around eight millennia," said senior author Andrea Manica from the University of Cambridge, who conducted the work with an international team, including colleagues from Ulsan National Institute of Science and Technology in Korea, and Trinity College Dublin and University College Dublin in Ireland.

"Once we accounted for some local intermingling, the Ulchi and the ancient hunter-gatherers appeared to be almost the same population from a genetic point of view, even though there are thousands of years between them."

The new study also provides further support for the 'dual origin' theory of modern Japanese populations: that they descend from a combination of hunter-gatherers and agriculturalists that eventually brought wet rice farming from southern China. A similar pattern is also found in neighbouring Koreans, who are genetically very close to Japanese.

However, Manica says that much more DNA data from Neolithic China is required to pinpoint the origin of the agriculturalists involved in this mixture.

The team from Trinity College Dublin were responsible for extracting DNA from the remains, which were found in a cave known as Devil's Gate. Situated in a mountainous area close to the far eastern coast of Russia that faces northern Japan, the cave was first excavated by a soviet team in 1973.

Along with hundreds of stone and bone tools, the carbonised wood of a former dwelling, and woven wild grass that is one of the earliest examples of a textile, were the incomplete bodies of five humans.

If ancient DNA can be found in sufficiently preserved remains, sequencing it involves sifting through the contamination of millennia. The best samples for analysis from Devil's Gate were obtained from the skulls of two females: one in her early twenties, the other close to fifty. The site itself dates back over 9,000 years, but the two women are estimated to have died around 7,700 years ago.

Researchers were able to glean the most from the middle-aged woman. Her DNA revealed she likely had brown eyes and thick, straight hair. She almost certainly lacked the ability to tolerate lactose, but was unlikely to have suffered from 'alcohol flush': the skin reaction to alcohol now common across East Asia.

While the Devil's Gate samples show high genetic affinity to the Ulchi, fishermen from the same area who speak the Tungusic language, they are also close to other Tungusic-speaking populations in present day China, such as the Oroqen and Hezhen.

"These are ethnic groups with traditional societies and deep roots across eastern Russia and China, whose culture, language and populations are rapidly dwindling," added lead author Veronika Siska, also from Cambridge.

"Our work suggests that these groups form a strong genetic lineage descending directly from the early Neolithic hunter-gatherers who inhabited the same region thousands of years previously."

Climate change drove population decline in New World before Europeans arrived

What caused the rapid disappearance of a vibrant Native American agrarian culture that lived in urban settlements from the Ohio River Valley to the Mississippi River Valley in the two centuries preceding the European settlement of North America? In a new study, researchers from Indiana University-Purdue University Indianapolis reconstructed and analyzed 2,100 years of temperature and precipitation data -- and point the finger at climate change.

Employing proxies of prehistoric temperature and precipitation preserved in finely layered lake sediments, somewhat analogous to tree-ring records used to reconstruct drought and temperature, the IUPUI scientists have reported on the dramatic environmental changes that occurred as the Native Americans -- known as Mississippians -- flourished and then vanished from the Midwestern United States. The researchers theorize that the catastrophic climate change they observed, which doomed food production, was a primary cause of the disappearance.

"Abrupt climate change can impose conditions like drought. If these conditions are severe and sustained, as we have determined that they became for the Mississippians, it is virtually impossible for societies, especially those based on agriculture, to survive," said paleoclimatologist Broxton Bird, corresponding author of the new study. "From the lake records, we saw that the abundant rainfall and consistent good weather -- which supported Mississippian society as it grew -- changed, making agriculture unsustainable." Bird is an assistant professor of earth sciences in the School of Science at IUPUI.

This failure of their principal food source likely destabilized the sociopolitical system that supported Mississippian society, according to archeologist Jeremy Wilson, a study co-author. He is an associate professor of anthropology in the School of Liberal Arts at IUPUI.

"Archeologists have recognized that from 1300 onward, Mississippian villages started disappearing -- one after the other -- almost like lightbulbs in a string, but the question has always been 'why?,'" said Wilson. "Dr. Bird and his students have shown from the lake-sediment evidence that during the period known as the Little Ice Age, from 1300 to 1800, there was a profound change in climate to colder and drier conditions, which would have negatively impacted the growing of maize in and around Mississippian villages.

"It's important for us to understand how past civilizations coped with climate change as we encounter things like changing precipitation patterns and temperatures that appear to be rising around the world today."

As the Mississippians' culture waned, the IUPUI researchers found, there were lower temperatures and significantly less summer rainfall than during its rise. They attribute these changes to more El Niño-like conditions in the Pacific Ocean and cooling during the Little Ice Age, which altered atmospheric circulation such that moisture delivered to the Midwest was derived from the northwestern U.S. (Pacific and Arctic) instead of the Gulf of Mexico, as was the case during the Mississippians' rise. The longer transport distance of Pacific air masses during the Little Ice Age left less moisture available for rainfall in the Midwest, resulting in drought conditions that undermined agricultural production.

"Climate change had been previously postulated as one of the factors responsible for the disappearance of the Mississippians," Bird said. "What our research did was develop the highest-resolution record yet produced of rainfall in the midcontinental U.S. for the last 2,100 years, including the time frame from the beginning of the Mississippian period -- about 1,000 years ago -- to 500 years ago, when much of the lower Midwest was totally abandoned by these people. Our results strongly support climate change -- drought, specifically -- as a significant cause of the disappearance of Mississippians from the midcontinent through its impact on their ability to farm and produce food surpluses.

"Mississippians did not have irrigation and relied on rainfall to grow their crops. Modern agriculture in the Midwest corn belt likewise relies on rainfall with very little irrigation infrastructure, making us similarly vulnerable to drought," Bird said.

"Midcontinental Native American Population Dynamics and Late Holocene Hydroclimate Extremes" is published in Scientific Reports, an open access, peer-reviewed Nature research journal.
The sediment studied was from Martin Lake in northeast Indiana. Bird and Wilson are continuing their research at additional lakes, especially those adjacent to archeological sites, throughout the midcontinent.