Wednesday, October 18, 2017

Research sheds new light on early turquoise mining in Southwest



Turquoise is an icon of the desert Southwest, with enduring cultural significance, especially for Native American communities. Yet, relatively little is known about the early history of turquoise procurement and exchange in the region.

University of Arizona researchers are starting to change that by blending archaeology and geochemistry to get a more complete picture of the mineral's mining and distribution in the region prior to the 16th-century arrival of the Spanish.

In a new paper, published in the November issue of the Journal of Archaeological Science, UA anthropology alumnus Saul Hedquist and his collaborators revisit what once was believed to be a relatively small turquoise mine in eastern Arizona. Their findings suggest that the Canyon Creek mine, located on the White Mountain Apache Indian Reservation, was actually a much more significant source of turquoise than previously thought.

With permission from the White Mountain Apache Tribe, Hedquist and his colleagues visited the now essentially exhausted Canyon Creek source -- which has been known to archaeologists since the 1930s -- to remap the area and collect new samples. There, they found evidence of previously undocumented mining areas, which suggest the output of the mine may have been 25 percent higher than past surveys indicated.

"Pre-Hispanic workings at Canyon Creek were much larger than previously estimated, so the mine was clearly an important source of turquoise while it was active," said Hedquist, lead author of the paper, who earned his doctorate from the UA School of Anthropology in the College of Social and Behavioral Sciences in May.

In addition, the researchers measured ratios of lead and strontium isotopes in samples they collected from the mine, and determined that Canyon Creek turquoise has a unique isotopic fingerprint that distinguishes it from other known turquoise sources in the Southwest. The isotopic analysis was conducted in the lab of UA College of Science Dean Joaquin Ruiz in the Department of Geosciences by study co-author and UA geosciences alumna Alyson Thibodeau. Now an assistant professor at Dickinson College in Pennsylvania, Thibodeau did her UA dissertation on isotopic fingerprinting of geological sources of turquoise throughout the Southwest.

"If you pick up a piece of turquoise from an archaeological site and say 'where does it come from?' you have to have some means of telling the different turquoise deposits apart," said David Killick, UA professor of anthropology, who co-authored the paper with Hedquist, Thibodeau and John Welch, a UA alumnus now on the faculty at Simon Fraser University. "Alyson's work shows that the major mining areas can be distinguished by measurement of major lead and strontium isotopic ratios."

Based on the isotopic analysis, researchers were able to confidently match turquoise samples they collected at Canyon Creek to several archaeological artifacts housed in museums. Their samples matched artifacts that had been uncovered at sites throughout much of east-central Arizona -- some more than 100 kilometers from the mine -- suggesting that distribution of Canyon Creek turquoise was broader than previously thought, and that the mine was a significant source of turquoise for pre-Hispanic inhabitants of the Mogollon Rim area.

The researchers also were able to pinpoint when the mine was most active. Their samples matched artifacts found at sites occupied between A.D. 1250-1400, suggesting the mine was primarily used in the late 13th and/or 14th centuries.

"Archaeologists have struggled for decades to find reliable means of sourcing archaeological turquoise -- linking turquoise artifacts to their geologic origin -- and exploring how turquoise was mined and traded throughout the greater pre-Hispanic Southwest," said Hedquist, who now lives in Tempe, Arizona, and works as an archaeologist and ethnographer for Logan Simpson Inc., a cultural resources consulting firm. "We used both archaeology and geochemistry to document the extent of workings at the mine, estimate the amount of labor spent at the mine and identify turquoise from the mine in archaeological assemblages."

Research Paves Way for Future Studies 

Turquoise is a copper mineral, found only immediately adjacent to copper ore deposits. While detailed documentation of pre-Hispanic turquoise mines is limited, the work at Canyon Creek could pave the way for future investigations.

"I think our study raises the bar a bit by combining archaeological and geochemical analyses to gain a more complete picture of operations at one mine: when it was active, how intensely it was mined and how its product moved about the landscape," Hedquist said. "Researchers have only recently developed a reliable means of sourcing the mineral, so there's plenty of potential for future research."

Similar work involving the UA is already underway to explore the origin of turquoise artifacts found at the Aztec capital of Tenochtitlan in Mexico.

"Canyon Creek is but one of many ancient turquoise mines," Hedquist said. "This study provides a standard for the detailed documentation of ancient mineral procurement and a framework for linking archaeological turquoise to specific geologic locations. Building on other archaeological patterns -- the circulation of pottery and flaked stone artifacts, for example -- we can piece together the social networks that facilitated the ancient circulation of turquoise in different times and places."

A better understanding of the pre-Hispanic history of turquoise is important not only to archaeologists and mining historians but to modern Native Americans, Killick said.

"It's of great interest to modern-day Apache, Zuni and Hopi, whose ancestors lived in this area, because turquoise continues to be ritually important for them," he said. "They really have shown a great deal of interest in this work, and they've encouraged it."

Friday, October 13, 2017

40,000-year-old man in China reveals complicated genetic history of Asia Chinese Academy


The biological makeup of humans in East Asia is shaping up to be a very complex story, with greater diversity and more distant contacts than previously known, according to a new study in Current Biology analyzing the genome of a man that died in the Tianyuan Cave near Beijing, China 40,000 years ago. His bones had enough DNA molecules left that a team led by Professor FU Qiaomei, at the Molecular Paleontology Lab at the Chinese Academy of Sciences Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), could use advanced ancient DNA sequencing techniques to retrieve DNA from him that spans the human genome.

Though several ancient humans have been sequenced in Europe and Siberia, few have been sequenced from East Asia, particularly China, where the archaeological record shows a rich history for early modern humans. This new study on the Tianyuan man marks the earliest ancient DNA from East Asia, and the first ancient genome-wide data from China.

The Tianyuan man was studied in 2013 by the same lab. Then, they found that he showed a closer relationship to present-day Asians than present-day Europeans, suggesting present-day Asian history in the region extends as far back as 40,000 years ago. With new molecular techniques only published in the last two years, Professor FU and her team, in a joint collaboration with experts at the Max Planck Institute of Evolutionary Anthropology and UC Berkeley, sequenced and analyzed more regions of the genome, particularly at positions also sequenced in other ancient humans.

Since 2013, DNA generated from ancient Europeans has shown that all present-day Europeans derive some of their population history from a prehistoric population that separated from other early non-African populations soon after the migration out of Africa. The mixed ancestry of present-day Europeans could bias tests of genetic similarity, including the results found for the Tianyuan man. With the newly published data, however, the Fu lab showed that his genetic similarity to Asians remained in comparisons including ancient Europeans without mixed ancestry. They confirmed that the closest relationship he shares is with present-day Asians. That was not, however, the most exciting result they found.

With a close relationship to present-day Asians, they expected him to act similarly to present-day Asian populations with respect to Europeans. It was a surprise when they found that a 35,000-year-old individual from Belgium, GoyetQ116-1, who in other ways behaved as an ancient European, shared some genetic similarity to the Tianyuan individual that no other ancient Europeans shared. It is unlikely that this is due to direct interactions between populations near the east and west coasts of Eurasia, since other ancient Europeans do not show a similar result. Instead, the researchers suggested that the two populations represented by the Tianyuan and GoyetQ116-1 individuals derived some of their ancestry from the same sub-population prior to the European-Asian separation. The genetic relationship observed between these two ancient individuals is direct evidence that European and Asian populations have a complex history.

A second unexpected result shed some light on human genetic diversity in prehistoric East Asia. In 2015, a study comparing present-day populations in Asia, the Pacific and the Americas showed that some Native American populations from South America had an unusual connection to some populations south of mainland Asia, most notably the Melanesian Papuan and the Andamanese Onge.
That study proposed that the population that crossed into the Americas around 20,000 years ago could not be thought of as a single unit. Instead, one or more related but distinct populations crossed at around the same time period, and at least one of these groups had additional ties to an Asian population that also contributed to the present-day Papuan and Onge.

No trace of this connection is observed in present-day East Asians and Siberians, but unlike them, the Tianyuan man also possesses genetic similarities to the same South Americans, in a pattern similar to that found for the Papuan and Onge. The new study directly confirms that the multiple ancestries represented in Native Americans were all from populations in mainland Asia. What is intriguing, however, is that the migration to the Americas occurred approximately 20,000 years ago, but the Tianyuan individual is twice that age. Thus, the population diversity represented in the Americas must have persisted in mainland Asia in two or more distinct populations since 40,000 years ago.

The Tianyuan man is only one individual, but the deeper sequencing of his genome by Professor FU and her team reveals a complicated separation for ancient Europeans and Asians and hints at a diverse genetic landscape for humans in East Asia. Their study also showed that he derives from a population that is related to present-day East Asians, but is not directly ancestral to these populations, further suggesting that multiple genetically distinct populations were located in Asia from 40,000 years ago until the present.

The Tianyuan man shows us that between 40,000 years ago and the present, there are many unanswered questions about the past populations of Asia, and ancient DNA will be the key solving those questions.

Thursday, October 12, 2017


Indigenous people have been on the far northeastern edge of Canada for most of the last 10,000 years, moving in shortly after the ice retreated from the Last Glacial Maximum. Archaeological evidence suggests that people with distinct cultural traditions inhabited the region at least three different times with a possible hiatus for a period between 2,000 and 3,000 years ago.


  • This schematic shows the settlement history of Newfoundland encompassing occupations by at least three distinct cultural groups: MA, Dorset Palaeoeskimo, and Beothuk.
  • Credit

  • Produced by Deirdre Elliott with QGIS 2.18.44, and data from Stephen Hull and Natural Earth.

Now, researchers who've examined genetic evidence from mitochondrial DNA provide evidence that two of those groups, known as the Maritime Archaic and Beothuk, brought different matrilines to the island, adding further support to the notion that those groups had distinct population histories. The findings are published in Current Biology on October 12.

"Our paper suggests, based purely on mitochondrial DNA, that the Maritime Archaic were not the direct ancestors of the Beothuk and that the two groups did not share a very recent common ancestor," says Ana Duggan of McMaster University. "This in turn implies that the island of Newfoundland was populated multiple times by distinct groups."

The relationship between the older Maritime Archaic population and Beothuk hadn't been clear from the archaeological record. With permission from the current-day indigenous community, Duggan and her colleagues, led by Hendrik Poinar, examined the mitochondrial genome diversity of 74 ancient remains from the island together with the archaeological record and dietary isotope profiles. All samples were collected from tiny amounts of bone or teeth.

The sample set included a Maritime Archaic subadult more than 7,700 years old found in the L'Anse Amour burial mound, the oldest known burial mound in North America and one of the first manifestations of the Maritime Archaic tradition. The majority of the Beothuk samples came from the Notre Dame Bay area, where the Beothuk retreated in response to European expansions. Most of those samples are from people that lived on the island within the last 300 years. The DNA evidence showed that the two groups didn't share a common maternal ancestor in the recent past, but rather one that coalesces sometime in the more distant past.

"These data clearly suggest that the Maritime Archaic people are not the direct maternal ancestors of the Beothuk and thus that the population history of the island involves multiple independent arrivals by indigenous peoples followed by habitation for many generations," the researchers write. "This shows the extremely rich population dynamics of early peoples on the furthest northeastern edge of the continent."

No trace of early contact between Rapanui and South Americans in ancient DNA


IMAGE
  • IMAGE: This photograph shows moai on Rapa Nui. view more 
    Credit: Terry Hunt
Rapa Nui (Easter Island, Chile) has long been a source of intrigue and mystery. How did such a small community of people build so many impressively large statues? And what happened to cause that community to collapse? Researchers have also been curious about what kind of contact Rapa Nui's inhabitants, known as Rapanui, might have had with South Americans prior to the arrival of Europeans. Earlier evidence seemed to support early contact between the Rapanui and Native Americans .

But a new study of ancient DNA evidence collected from archaeological samples and reported in Current Biology on October 12th calls those findings back into question. The new study finds no genetic evidence that ancient inhabitants of Rapa Nui intermixed with South Americans. While the findings can't exclude the possibility that cultural contact took place between the two populations, if long-distance treks across the ocean did occur, "they did not leave genetic traces among the individual samples," said Lars Fehren-Schmitz of the University of California, Santa Cruz. "We were surprised that we didn't find any Native American admixture in our ancient Rapanui specimens."

The idea that there had been early Pacific contact with South America, or even that a Southern Pacific migration route contributed to the peopling of the Americas, has been a long-standing debate in the field. In their new study, Fehren-Schmitz and colleagues wanted to find out what DNA from ancient Rapanui samples had to say on the matter.

The researchers sequenced DNA from five individual samples representing Rapanui both before and after European contact. They report that the DNA, including both complete mitochondrial genomes and low-coverage autosomal genomes, indicates that the DNA of the sampled individuals falls within the genetic diversity of present-day and ancient Polynesians.

"We can reject the hypothesis that any of these individuals had substantial Native American ancestry," Fehren-Schmitz said. "Our data thus suggest that the Native American ancestry in contemporary Easter Islanders was not present on the island prior to European contact and may thus be due to events in more recent history."

The new study highlights the value of ancient DNA for testing hypotheses about the past. It's clear from earlier evidence that living Rapanui do have a small proportion of Native American ancestry. But, the researchers in the new study say, "it is especially difficult to disentangle movements of people in the prehistoric period from more recent times." The question remains: How and when did this population exchange happen?

The researchers say they'd now like to generate genome-wide data from additional ancient Oceania and western South American populations. The goal is to develop a more detailed picture of the populations that lived within each of these regions and potential interactions among them.

Monday, October 9, 2017

Amazon farmers discovered the secret of domesticating wild rice 4,000 years ago

                     


Amazonian farmers discovered how to manipulate wild rice so the plants could provide more food 4,000 years ago, long before Europeans colonised America, archaeologists have discovered.

Experts from the UK and Brazil have found the first evidence that ancient South Americans learned how to grow bigger rice crops with larger grains, but this expertise may have been lost after 1492 when the indigenous population was decimated, research shows.

The evidence of the success of early rice farmers on the vast wetlands near the Guaporé River in Rondônia state, Brazil, could help modern day plant breeders develop rice crops which are less susceptible to disease and more adaptable to the effects of climate change than the Asian varieties. Different species of rice were first grown approximately 11,000 years ago in the Yangtze River, China, and around 2,000 years ago in West Africa.

The University of Exeter study, funded in part by the European Research Council, also shows how important the huge wetlands and tropical forests of lowland South America were in providing food for early human settlers in South America. Ancient inhabitants managed to domesticate cassava, peanuts and chilli peppers crops for food.

The archaeologists analysed 16 samples of microscopic plant remains from ten different time periods found during excavations during 2014 led by the University of São Paulo in South West Amazonia. More phytoliths, hard, microscopic pieces of silica made by plant cells, were found at higher ground level, suggesting rice began to play a larger role in the diet of people who lived in the area - and more was farmed - as time went on.

Changes in the ratio of husk, leaf and stem remains found at different ground levels also suggest the Amazon residents became more efficient harvesters over time, bringing more grain and fewer leaves to the site. The rice grown, Oryza sp, also became bigger over time compared to the wild rice first cultivated by the South Americans. This area has been occupied by humans for at least 10,000 years.

Professor Jose Iriarte, from the University of Exeter, who led the research, said: "This is the first study to identify when wild rice first began to be grown for food in South America. We have found people were growing crops with larger and larger seeds. Even though they were also eating wild and domesticated plants including maize, palm fruits, soursop and squash, wild rice was an important food, and people began to grow it at lake or river edges.

"During a time when the climate was getting wetter and the wetlands expanding, this critical seasonal resource that is ripe at the peak of the flooding season when other resources are dispersed and scarce, residents of Monte Castelo began to grow larger rice."

Evidence for mid-Holocene rice domestication in the Americas by Lautaro Hilbert and Jose Iriarte from the University of Exeter, Elizabeth Veasey, Carlos Augusto Zimpel, Eduardo Goes Neves and Francisco Pugliese from the Universidade de São Paulo, Bronwen S. Whitney from Northumbria University and Myrtle Shock from the Universidade Federal do Oeste de Pará, is published in the journal Nature Ecology and Evolution

Friday, October 6, 2017

More traits associated with your Neandertal DNA


After humans and Neandertals met many thousands of years ago, the two species began interbreeding. Although Neandertals aren't around anymore, about two percent of the DNA in non-African people living today comes from them. Recent studies have shown that some of those Neandertal genes have contributed to human immunity and modern diseases. Now researchers reporting in the American Journal of Human Genetics on October 5th have found that our Neandertal inheritance has contributed to other characteristics, too, including skin tone, hair color, sleep patterns, mood, and even a person's smoking status.

Inspired by an earlier study that found associations between Neandertal DNA and disease risk, Janet Kelso at the Max Planck Institute for Evolutionary Anthropology in Germany says her team was interested in exploring connections between Neandertal DNA and traits unrelated to disease. In other words, they wanted to uncover the "influence Neandertal DNA might be having on ordinary variation in people today."

Because Neandertal alleles are relatively rare, the researchers needed data representing a really large number of people. They found what they were looking for in data representing more than 112,000 participants in the UK Biobank pilot study. The Biobank includes genetic data along with information on many traits related to physical appearance, diet, sun exposure, behavior, and disease.

Earlier studies had suggested that human genes involved in skin and hair biology were strongly influenced by Neandertal DNA, Kelso says. But it hadn't been clear how.

"We can now show that it is skin tone, and the ease with which one tans, as well as hair color that are affected," Kelso says.

The researchers observe multiple different Neandertal alleles contributing to skin and hair tones. What they found somewhat surprising is that some Neandertal alleles are associated with lighter skin tones and others with darker skin tones. The same was true for hair color.

"These findings suggest that Neandertals might have differed in their hair and skin tones, much as people now do" adds Michael Dannemann, first author of the study.

Kelso notes that the traits influenced by Neandertal DNA, including skin and hair pigmentation, mood, and sleeping patterns are all linked to sunlight exposure. When modern humans arrived in Eurasia about 100,000 years ago, Neandertals had already lived there for thousands of years. They were likely well adapted to lower and more variable levels of ultraviolet radiation from the sun than the new human arrivals from Africa were accustomed to.

"Skin and hair color, circadian rhythms and mood are all influenced by light exposure," the researchers wrote. "We speculate that their identification in our analysis suggests that sun exposure may have shaped Neandertal phenotypes and that gene flow into modern humans continues to contribute to variation in these traits today."

Kelso and her colleagues say they'll continue to explore Neandertals' influence on modern-day traits as more data becomes available.

New Neandertal genomes advance our understanding of human evolution


Two new studies on ancient genomes provide valuable insights into the lives of our ancestors and their cousins, the Neandertals. First, scientists have sequenced a new genome of a female Neandertal, which is only the second genome of the species to be fully sequenced with such a high level of quality. The advancement confirms a number of theories about Neandertals, but also reveals new genetic contributions of the species to modern-day humans. Neandertals are the closest evolutionary relatives of all present-day humans and therefore provide a unique perspective on human biology and history. Five Neandertal genomes have been sequenced to date, yet only one yielded high-quality data, an individual found in Siberia known as the "Altai Neandertal."

Three less well-defined genomes come from individuals found in a cave, Vindija, in Croatia, and one from Mezmaiskaya Cave, in Russia. Here, Kay Prüfer and colleagues successfully analyzed billions of DNA fragments sampled from a new individual in the Croatian cave, dubbed Vindija 33.19, a female who lived roughly 52,000 years ago. Similar to previous findings, the genetic data suggest that Neandertals lived in small and isolated populations of about 3,000 individuals.

The previously sequenced Altai Neandertal genome suggested that the individual's parents were half-siblings, prompting scientists to wonder if Neandertals commonly interbred with family members - yet the new Vindija genome does not have similar incestual patterns, suggesting that the extreme inbreeding between the parents of the Altai Neandertal may not have been ubiquitous among Neandertals. Vindija 33.19 does appear to share a maternal ancestor with two of the three other individuals from the Croatian cave who were genetically sequenced, however.

The authors use the Vindija 33.19 genome to analyze divergences and gene flow among Neandertals, Denisovans (another extinct species of hominin), and modern humans. Among many findings, they report that early modern human gene flow into Neandertal populations occurred between 130,000 and 145,000 years ago, before the Croatian and Siberian Neandertals diverged.

Based on the new high-quality genome, the authors estimate that modern non-African populations carry between 1.8-2.6% Neandertal DNA, which is higher than previous estimates of 1.5-2.1%.

Lastly, they identify a wealth of new gene variants in the Neandertal genome that are influential in modern day humans, including variants related to plasma levels of LDL cholesterol and vitamin D, eating disorders, visceral fat accumulation, rheumatoid arthritis, schizophrenia and responses to antipsychotic drugs.

Prehistoric humans are likely to have formed mating networks to avoid inbreeding


Early humans seem to have recognised the dangers of inbreeding at least 34,000 years ago, and developed surprisingly sophisticated social and mating networks to avoid it, new research has found.
The study, reported in the journal Science, examined genetic information from the remains of anatomically modern humans who lived during the Upper Palaeolithic, a period when modern humans from Africa first colonised western Eurasia. The results suggest that people deliberately sought partners beyond their immediate family, and that they were probably connected to a wider network of groups from within which mates were chosen, in order to avoid becoming inbred.
This suggests that our distant ancestors are likely to have been aware of the dangers of inbreeding, and purposely avoided it at a surprisingly early stage in prehistory.

The symbolism, complexity and time invested in the objects and jewellery found buried with the remains also suggests that it is possible that they developed rules, ceremonies and rituals to accompany the exchange of mates between groups, which perhaps foreshadowed modern marriage ceremonies, and may have been similar to those still practised by hunter-gatherer communities in parts of the world today.

The study's authors also hint that the early development of more complex mating systems may at least partly explain why anatomically modern humans proved successful while other species, such as Neanderthals, did not. However, more ancient genomic information from both early humans and Neanderthals is needed to test this idea.

The research was carried out by an international team of academics, led by the University of Cambridge, UK, and the University of Copenhagen, Denmark. They sequenced the genomes of four individuals from Sunghir, a famous Upper Palaeolithic site in Russia, which is believed to have been inhabited about 34,000 years ago.

The human fossils buried at Sunghir represent a rare and highly valuable, source of information because very unusually for finds from this period, the people buried there appear to have lived at the same time and were buried together. To the researchers' surprise, however, these individuals were not closely related in genetic terms; at the very most, they were second cousins. This is true even in the case of two children who were buried head-to-head in the same grave.

Professor Eske Willerslev, who holds posts both as a Fellow at St John's College, Cambridge, and at the University of Copenhagen, was the senior author on the study.

What this means is that even people in the Upper Palaeolithic, who were living in tiny groups, understood the importance of avoiding inbreeding, he said.

The data that we have suggest that it was being purposely avoided.

This means that they must have developed a system for this purpose. If small hunter-gatherer bands were mixing at random, we would see much greater evidence of inbreeding than we have here.
Early humans and other hominins such as Neanderthals appear to have lived in small family units. The small population size made inbreeding likely, but among anatomically modern humans it eventually ceased to be commonplace; when this happened, however, is unclear.

Small family bands are likely to have interconnected with larger networks, facilitating the exchange of people between groups in order to maintain diversity, Professor Martin Sikora, from the Centre for GeoGenetics at the University of Copenhagen, said.

Sunghir contains the burials of one adult male and two younger individuals, accompanied by the symbolically-modified incomplete remains of another adult, as well as a spectacular array of grave goods. The researchers were able to sequence the complete genomes of the four individuals, all of whom were probably living on the site at the same time. These data were compared with information from a large number of both modern and ancient human genomes.

They found that the four individuals studied were genetically no closer than second cousins, while an adult femur filled with red ochre found in the children's' grave would have belonged to an individual no closer than great-great grandfather of the boys.

This goes against what many would have predicted, Willerslev said.

I think many researchers had assumed that the people of Sunghir were very closely related, especially the two youngsters from the same grave.

The people at Sunghir may have been part of a network similar to that of modern day hunter-gatherers, such as Aboriginal Australians and some historical Native American societies. Like their Upper Palaeolithic ancestors, these people live in fairly small groups of around 25 people, but they are also less directly connected to a larger community of perhaps 200 people, within which there are rules governing with whom individuals can form partnerships.

Most non-human primate societies are organised around single-sex kin where one of the sexes remains resident and the other migrates to another group, minimising inbreeding says Professor Marta Mirazón Lahr, from the Leverhulme Centre for Human Evolutionary Studies at the University of Cambridge.

At some point, early human societies changed their mating system into one in which a large number of the individuals that form small hunter-gatherer units are non-kin. The results from Sunghir show that Upper Palaeolithic human groups could use sophisticated cultural systems to sustain very small group sizes by embedding them in a wide social network of other groups.

By comparison, genomic sequencing of a Neanderthal individual from the Altai Mountains who lived around 50,000 years ago indicates that inbreeding was not avoided. This leads the researchers to speculate that an early, systematic approach to preventing inbreeding may have helped anatomically modern humans to thrive, compared with other hominins.

This should be treated with caution, however:

We don't know why the Altai Neanderthal groups were inbred, Sikora said.

Maybe they were isolated and that was the only option; or maybe they really did fail to develop an available network of connections. We will need more genomic data of diverse Neanderthal populations to be sure.

Willerslev also highlights a possible link with the unusual sophistication of the ornaments and cultural objects found at Sunghir. Group-specific cultural expressions may have been used to establish distinctions between bands of early humans, providing a means of identifying who to mate with and who to avoid as partners.

The ornamentation is incredible and there is no evidence of anything like that with Neanderthals and other archaic humans, Willerslev added.

When you put the evidence together, it seems to be speaking to us about the really big questions; what made these people who they were as a species, and who we are as a result.

The research paper, Ancient genomes show social and reproductive behaviour of early Upper Paleolithic foragers, is published in the October 5 issue of Science.

Wednesday, October 4, 2017

Ornamented artifact may indicate long-distance exchange between Mesolithic communities



Caption

This is an ornamented bâton percé.

Credit

Osipowicz et al (2017)


An ornamented bâton percé found in Central Poland may provide evidence of exchange between Mesolithic communities, according to a study published October 4, 2017 in the open-access journal PLOS ONE : http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184560by Grzegorz Osipowicz from Nicolaus Copernicus University, Poland, and colleagues.

Artifacts and raw materials can provide insight into how Prehistoric communities exchanged gifts, such as stone transported for its technological significance, or metal products adorning graves. Recently, researchers found an ornamented bâton percé carved from antler of unknown origin in the Go??biewo site in Central Poland.

To investigate the antler source species and its geographic origin, the researchers conducted DNA and stable isotope analyses of the artifact. The source material was identified as antler from a reindeer species which dispersion analysis revealed to have a range limited to northern Scandinavia and north-western Russia during the Early-Holocene. This may suggest that the artifact was transported from North Karelia to Central Poland.

The reasons why this artifact was transported are subject to speculation, but the authors suggest that their results are possible evidence for the flow of goods between hunter-gatherer groups at a large distance. This study provides new insight into how ideas and items were exchanged in Mesolithic communities within North Eastern Europe.

"The route taken for transporting the Rangifer tarandus antler from nearby North Karelia to Central Poland, and the motive for transporting it, remain impossible to determine conclusively," says Osipowicz. "However, the obtained results are the first direct evidence for the flow of goods between hunter-gatherer groups in the Early Holocene at such a great distance."

Ancient humans left Africa to escape drying climate


Humans migrated out of Africa as the climate shifted from wet to very dry about 60,000 years ago, according to research led by a University of Arizona geoscientist.

Genetic research indicates people migrated from Africa into Eurasia between 70,000 and 55,000 years ago. Previous researchers suggested the climate must have been wetter than it is now for people to migrate to Eurasia by crossing the Horn of Africa and the Middle East.

"There's always been a question about whether climate change had any influence on when our species left Africa," said Jessica Tierney, UA associate professor of geosciences. "Our data suggest that when most of our species left Africa, it was dry and not wet in northeast Africa."

Tierney and her colleagues found that around 70,000 years ago, climate in the Horn of Africa shifted from a wet phase called "Green Sahara" to even drier than the region is now. The region also became colder.

The researchers traced the Horn of Africa's climate 200,000 years into the past by analyzing a core of ocean sediment taken in the western end of the Gulf of Aden. Tierney said before this research there was no record of the climate of northeast Africa back to the time of human migration out of Africa.
"Our data say the migration comes after a big environmental change. Perhaps people left because the environment was deteriorating," she said. "There was a big shift to dry and that could have been a motivating force for migration."

"It's interesting to think about how our ancestors interacted with climate," she said.

The team's paper, "A climatic context for the out-of-Africa migration," is published online in Geology this week. Tierney's co-authors are Peter deMenocal of the Lamont-Doherty Earth Observatory in Palisades, New York, and Paul Zander of the UA.

The National Science Foundation and the David and Lucile Packard Foundation funded the research.
Tierney and her colleagues had successfully revealed the Horn of Africa's climate back to 40,000 years ago by studying cores of marine sediment. The team hoped to use the same means to reconstruct the region's climate back to the time 55,000 to 70,000 years ago when our ancestors left Africa.

The first challenge was finding a core from that region with sediments that old. The researchers enlisted the help of the curators of the Lamont-Doherty Core Repository, which has sediment cores from every major ocean and sea. The curators found a core collected off the Horn of Africa in 1965 from the R/V Robert D. Conrad that might be suitable.

Co-author deMenocal studied and dated the layers of the 1965 core and found it had sediments going back as far as 200,000 years.

At the UA, Tierney and Paul Zander teased out temperature and rainfall records from the organic matter preserved in the sediment layers. The scientists took samples from the core about every four inches (10 cm), a distance that represented about every 1,600 years.

To construct a long-term temperature record for the Horn of Africa, the researchers analyzed the sediment layers for chemicals called alkenones made by a particular kind of marine algae. The algae change the composition of the alkenones depending on the water temperature. The ratio of the different alkenones indicates the sea surface temperature when the algae were alive and also reflects regional temperatures, Tierney said.

To figure out the region's ancient rainfall patterns from the sediment core, the researchers analyzed the ancient leaf wax that had blown into the ocean from terrestrial plants. Because plants alter the chemical composition of the wax on their leaves depending on how dry or wet the climate is, the leaf wax from the sediment core's layers provides a record of past fluctuations in rainfall.

The analyses showed that the time people migrated out of Africa coincided with a big shift to a much drier and colder climate, Tierney said.

The team's findings are corroborated by research from other investigators who reconstructed past regional climate by using data gathered from a cave formation in Israel and a sediment core from the eastern Mediterranean. Those findings suggest that it was dry everywhere in northeast Africa, she said.

"Our main point is kind of simple," Tierney said. "We think it was dry when people left Africa and went on to other parts of the world, and that the transition from a Green Sahara to dry was a motivating force for people to leave."

Major Exhibition of Artifacts from the Ancient City of Teotihuacan, Many Recently Excavated or Never Before Seen in the U.S.


de Young Museum in San Francisco 

September 30, 2017, through February 11, 2018

 

Los Angeles County Museum of Art (LACMA) 

March 25 through July 15, 2018

Circular relief, 300–450. Stone. Museo Nacional de Antropología
  • Circular relief, 300–450. Stone, 49 1/4 x 40 1/2 x 9 7/8 in. (125 x 103 x 25 cm). Museo Nacional de Antropología / INAH, 10-81807. Archivo Digital de las Colecciones del Museo Nacional de Antropología / INAH-CANON
The Fine Arts Museums of San Francisco (FAMSF) are pleased to premiere Teotihuacan: City of Water, City of Fire, the first major U.S. exhibition on Teotihuacan in over twenty years. The ancient metropolis of Teotihuacan is one of the largest and most important archaeological sites in the world, and the most-visited archaeological site in Mexico. At its peak in 400 CE, Teotihuacan was the cultural, political, economic, and religious center of Mesoamerica and inhabited by a multiethnic population of more than 100,000 people. This historic exhibition will feature more than 200 artifacts and artworks from the site and is a rare opportunity to view objects drawn from major collections in Mexico, some recently excavated – many on view in the U.S. for the first time – together in one spectacular exhibition.
 
“We are proud to have been working in collaboration with our cultural partners in Mexico for over 30 years,” says Max Hollein, Director and CEO of FAMSF. “In this groundbreaking exhibition, an abundance of recent archaeological discoveries will offer visitors to the de Young insight into the life of the ancient city and give greater context and significance to the Teotihuacan murals in our own collection.”
Located approximately 30 miles outside of modern-day Mexico City, Teotihuacan was founded in the first century BCE near a set of natural springs in an otherwise arid corner of the Valley of Mexico. At its height  a few centuries later, the city covered nearly eight square miles and featured enormous pyramids, long avenues, and residential compounds. Highlights of the exhibition will include artifacts recently excavated from the site of the Feathered Serpent Pyramid, as well as objects from both recent and historic excavations of the Moon Pyramid, and the Sun Pyramid—the three largest pyramids at Teotihuacan.
The exhibition, which will travel to the Los Angeles County Museum of Art (LACMA), will also reunite exquisite mural fragments in FAMSF’s collection with others originating from the same residential compound at Teotihuacan. In 1986, FAMSF repatriated a number of murals as part of an unprecedented joint agreement with Mexico’s National Institute of Anthropology and History (INAH). Together they established a program of collaborative conservation and exhibition. Alongside these murals will be monumental and ritual objects from the three pyramids, as well as ceramics and stone sculptures from the city’s apartment compounds, which were inhabited by diverse peoples from many parts of Mexico.
“The past ten years have seen major revelations in Teotihuacan archaeology. With these discoveries comes a new sense of Teotihuacan that will have an impact for generations to come,” says Diego Prieto Hernández, INAH General Director. “We are grateful for the enthusiastic and abiding partnerships we have developed with the Fine Arts Museums of San Francisco and the Los Angeles County Museum of Art. Such exchanges are crucial to create a shared understanding and vision across countries and cultures, a common basis for our human experience."
The national and international teams working at the main pyramids have made significant discoveries since the last major Teotihuacan exhibition in 1993, when the de Young hosted Teotihuacan: Art from the City of the Gods. By bringing objects from various excavations together and encouraging visitors to understand the context of specific sites within the city, the new exhibition will provide a rare opportunity for Bay Area audiences and visitors to experience a significant place in Mexico's historical and cultural landscape.

“This exhibition will give visitors the chance to be immersed in the history of Teotihuacan and its urbanism through encounters with 200 objects,” says exhibition curator Matthew H. Robb. “It is an opportunity to anchor these objects on the map of the site to understand how art held communities together in a large, complex, cosmopolitan city— offering valuable lessons for contemporary audiences.”

In the sixth century, a devastating fire in the city center led to Teotihuacan’s rapid decline, but the city was never completely abandoned or forgotten; the Aztecs revered the city and its monuments, giving many of them the names we still use today. Teotihuacan is now a UNESCO World Heritage Site and attracts upwards of four million visitors annually.

Teotihuacan: City of Water, City of Fire is curated by Matthew H. Robb, chief curator of the Fowler Museum at UCLA and former curator of the arts of the Americas at FAMSF.

In Detail
 
Teotihuacan: City of Water, City of Fire brings together art and artifacts from recent excavations with objects found as long as a century ago. These finely crafted works demonstrate how the city’s dominant ideology permeated everyday spaces, united a diverse population, and provided a guide for citizens as they navigated Teotihuacan’s streets. The Aztecs revered Teotihuacan and gave the city and its major monuments their names. This exhibition is organized geographically around these places.


The exhibition begins with recent discoveries from a tunnel found underneath the Feathered Serpent Pyramid by Mexican archaeologists in 2003. Over a decade of explorations yielded an astonishing array of objects: enigmatic sculptures that may represent Teotihuacan’s founding ancestors and large quantities of vessels depicting one of Teotihuacan’s most important deities, the Storm God. Shells likely originating from the Gulf of Mexico were also found, some incised with designs from other parts of Mesoamerica, indicating that even early in its history Teotihuacan was already a major regional hub.

Teotihuacan was a highly organized city, built in a grid like plan over roughly eight square miles, situated along the north-south axis formed by the Street of the Dead, and made up largely of architecturally similar single-story residential buildings varying in size and level of luxury. These apartment compounds housed many of Teotihuacan’s residents. 

The first gallery introduces the art forms for which Teotihuacan is best known and highlights important deities, including the Storm God, with his goggle eyes and distinctive nose plaque; the Old Fire God, an elderly figure who sits cross-legged and bears a brazier atop his head; the Water Goddess, known from large monuments; and the Maize God, who symbolized the life-sustaining power of this crop and may be the subject of Teotihuacan’s famous stone masks.

The next gallery showcases objects from a range of residential compounds, demonstrating aspects of daily and ceremonial life for Teotihuacan’s citizens. Immigrant groups from across Mesoamerica frequently occupied distinct neighborhoods, or barrios. Here they maintained traditions from their places of origin and simultaneously integrated themselves into the fabric of the city and its dominant ideology. In a compound on the city’s western edge, for example, people from Oaxaca carried out Zapotec lifeways, including the use of Zapotec calendrical signs. An offering on the city’s eastern edge included delicately painted ceramic figurines of women and infants. And on the city’s southern periphery, the working-class residents of Tlajinga specialized in the mass production of utilitarian obsidian blades and played a crucial role in Teotihuacan’s economy.

  • Tripod vessel with blowgunner, 450–550. Ceramic with post-fire stucco and pigment, 5 3/8 x 5 3/4 in. (13.7 x 14.6 cm). Los Angeles County Museum of Art, Gift of Constance McCormick Fearing, AC1998.209.15. Photo © Museum Associates / LACMA Image courtesy of the Fine Arts Museums of San Francisco

La Ventilla, to the southwest of Teotihuacan’s ceremonial core, is presented as an archetypal Teotihuacan residential area. Artisans from La Ventilla created spectacular artworks to satisfy local and regional markets. These included iconic ceramic tripod vessels and elaborate incense burners—or incensarios. More incensarios have been found at La Ventilla than anywhere else in the city. They were often decorated with mass-produced, mold-made clay decorations that were applied to their surfaces.

The Feathered Serpent Pyramid and the surrounding Ciudadela are next explored. Though smaller in comparison to the Sun and Moon Pyramids, the Feathered Serpent Pyramid was covered in elaborate, monumental carvings of undulating serpents. At the time of its construction, around 250 CE, a series of large-scale sacrificial offerings were made, including the burial of more than 200 individuals. Many of the victims wore necklaces of shell carved to look like human teeth—a few included actual human jawbones – and were discovered in positions that imply they were tied and bound at the time of death. These sacrifices suggest an era of significant military might at Teotihuacan.


  • View of the Sun Pyramid looking east. At 63 meters tall, the Sun Pyramid was one of the largest and tallest structures in the Western Hemisphere until the development of the skyscraper in the nineteenth century. Photograph by Jorge Pérez de Lara Elías, © INAH Image courtesy of the Fine Arts Museums of San Francisco

The Sun Pyramid is Teotihuacan’s largest structure and one of the largest ever built in the ancient world. It rises about 206 feet high and was built in one single, massive construction effort around 200 CE. Recent excavations have uncovered offerings of greenstone objects and evidence for programs of exterior sculpture depicting motifs related to fire and jaguars. Large pieces have also been discovered at the pyramid’s summit, including a statue of the Old Fire God—a deity with deep roots in central Mexico; early Teotihuacan leaders sought to bind the different ethnic groups inhabiting the city together by creating a single, modified version of the Old Fire God.

  • Feathered Serpents and Flowering Trees mural (Feathered Serpent 1), 500–550. Earthen aggregate, stucco, and mineral pigments, 22 1/4 x 160 1/4 in (56.5 x 407 cm). Fine Arts Museums of San Francisco, Bequest of Harald J. Wagner, 1985.104a Image courtesy of the Fine Arts Museums of San Francisco
After its monumental architecture, Teotihuacan is perhaps best known for its complex fresco murals, which decorated the city’s apartments and administrative centers. Stunning murals from high-status compounds in the Techinantitla section just east of the Moon Pyramid are on view in the next gallery, featuring exceptional mural fragments from FAMSF’s collection reunited with others from the same compound.



  • Mexico, Anahuac, Teotihuacan, Moon Pyramid. (Photo by: Eye Ubiquitous/UIG via Getty Images) Image courtesy of the Fine Arts Museums of San Francisco

The Moon Pyramid, Teotihuacan’s second-largest structure, at a height of approximately 141 feet, is explored next. Excavations there have revealed a seven-phase construction sequence beginning sometime between 50 and 150 CE, with the monument achieving its largest size between 300 and 400 CE. During the fourth phase of construction, the pyramid was greatly enlarged, indicating a period of increasing wealth and political centralization. 

The completion of the construction was marked by a dedication event that involved the sacrifice of many humans and predatory animals. The sacrificial offering also included objects made of exceptionally precious materials such as greenstone, obsidian, slate, and pyrite. Many of these offerings, which were carefully arranged, seem to have connections to rituals relating to the origin of the cosmos.

The exhibition concludes at the compound of Xalla, located to the east of the Moon Pyramid plaza and just north of the Sun Pyramid. The compound was likely a site for the city’s powerful ruling elite, indicated by its architectural complexity and the large quantity of ornamental sculpture found there. Many objects from Xalla bear evidence of a violently destructive event that marked the beginning of Teotihuacan’s collapse. 

 At around 550 CE, the ceremonial center of the city was burned; ritual objects, such as the large marble sculpture shown in the final gallery, were intentionally smashed and scattered. After the great fire, the systems of urban and religious maintenance that had been successful for more than 400 years fell apart. Much of the population left the city, and Teotihuacan’s regional dominance ended. But the site itself was never forgotten, and its legacy lives on as a powerful model of ancient Mesoamerican urbanism.

Friday, September 29, 2017

Scandinavia's earliest farmers exchanged terminology with Indo-Europeans


5,000 years ago, the Yamnaya culture migrated into Europe from the Caspian steppe. In addition to innovations such as the wagon and dairy production, they brought a new language - Indo-European - that replaced most local languages the following millennia. But local cultures also influenced the new language, particularly in southern Scandinavia, where Neolithic farmers made lasting contributions to Indo-European vocabulary before their own language went extinct, new research shows.

Most historical linguists agree that words such as 'wheel', 'wagon', 'horse', 'sheep', 'cow', 'milk' and 'wool' can be attributed to the Yamnaya people who migrated into Europe from the Caspian steppe 5,000 years ago. The nomadic and pastoral Yamnayans introduced their material culture to the local peoples through a new language known as Proto-Indo-European, from which most European languages descend.

However, not all words in the European languages are of Proto-Indo-European origin, linguists say; there are words for flora and fauna, which must have been incorporated into Indo-European from local cultures. But where could such cultural exchange have taken place? According to a new study published in American Journal of Archaeology by archaeologist Rune Iversen and linguist Guus Kroonen from the University of Copenhagen, southern Scandinavia 2,800 BC provides an ideal setting for such an exchange:

"The archaeological evidence tells us that between 2,800 and 2,600 BC two very different cultures co-existed in southern Scandinavia: there was the local, Neolithic culture known as the Funnel Beaker Culture with its characteristic funnel-shaped ceramics and collective burial practices and the new Single Grave Culture influenced by the Yamnaya culture. The Funnel Beaker Culture was eventually superseded by the Single Grave Culture, but the transition took hundreds of years in the eastern part of southern Scandinavia, and the two cultures must have influenced each other during this time, "says archaeologist Rune Iversen, who has specialised in this particular transitional period.



This is a schematic impression of how the different Indo-European branches may have absorbed lexical items (circles) from previously spoken languages in the linguistically complex setting of Europe from the third millennium BC.

Credit

University of Copenhagen
Peas, beans, turnips and shrimps
Historical linguist Guus Kroonen points to a number of words for local flora and fauna and important plant domesticates that the incoming speakers of Indo-European could not have brought with them to southern Scandinavia.

"There is a cluster of words in European languages such as Danish, English, and German - the Germanic languages - which stand out because they do not conform to the established sound changes of Indo-European vocabulary. It is words like sturgeon, shrimp, pea, bean and turnip that cannot be reconstructed to the Proto-Indo-European ancestor," Guus Kroonen explains and adds:

"This tells us that these words must have entered Indo-European after it had spread from the Caspian steppe to the various parts of Europe. In other words: the new Single Grave Culture is likely to have adopted much farming and hunting terminology from the local Funnel Beaker Culture that inhabited southern Scandinavia and Denmark till around 2,600 BC. When Indo-European in Northern Europe developed into Proto-Germanic, the terminology for local flora and fauna was preserved, which is why we know and can study the terms today."
Guus Kroonen adds that this farming terminology may be vestiges of a now extinct language spoken by the people who initially brought farming to Europe from Anatolia 9,000-6,000 years ago.

Thursday, September 28, 2017

Modern humans emerged more than 300,000 years ago


A genomic analysis of ancient human remains from KwaZulu-Natal revealed that southern Africa has an important role to play in writing the history of humankind. A research team from Uppsala University, Sweden, the Universities of Johannesburg and the Witwatersrand, South Africa, presents their results in the September 28th early online issue of Science.

The team sequenced the genomes of seven individuals who lived in southern Africa 2300-300 years ago. The three oldest individuals dating to 2300-1800 years ago were genetically related to the descendants of the southern Khoe-San groups, and the four younger individuals who lived 500-300 years ago were genetically related to current-day South African Bantu-speaking groups.

"This illustrates the population replacement that occurred in southern Africa", says co-first author Carina Schlebusch, population geneticist at Uppsala University.


Because the boy from Ballito Bay was of hunter-gatherer descent, living at a time before migrants from further north in Africa reached South African shores, his DNA could be used to estimate the split between modern humans and earlier human groups as occurring between 350 000 and 260 000 years ago.

"This means that modern humans emerged earlier than previously thought", says Mattias Jakobsson, population geneticist at Uppsala University, who headed the project together with Marlize Lombard from the University of Johannesburg.

The 350 000 to 260 000 years estimate also coincides with the Florisbad skull, who was a contemporary of the small-brained Homo naledi in South Africa. "It now seems that at least two or three Homo species occupied the southern African landscape during this time, which also represents the early phases of the Middle Stone Age", says Lombard.

Cumulatively, the fossil, ancient DNA and archaeological records indicate that the transition from archaic to modern humans might not have occurred in only one place in Africa. Instead, regions including southern and northern Africa (as recently reported) probably played a role.

"Thus, both palaeo-anthropological and genetic evidence increasingly points to multiregional origins of anatomically modern humans in Africa, i.e. Homo sapiens did not originate in one place in Africa, but might have evolved from older forms in several places on the continent with gene flow between groups from different places", says Carina Schlebusch.

These findings from South Africa shed new light on our species' deep African history and show that there is still much more to learn about our process of becoming modern humans. The results of this study also emphasise that the interplay between genetics and archaeology has an increasingly important role to play.

The authors estimate the divergence among modern humans to have occurred between 350,000 and 260,000 years ago, based on the ancient Stone Age hunter-gatherer genomes. The deepest split time of 350,000 years ago represents a comparison between an ancient Stone Age hunter-gatherer boy from Ballito Bay on the east coast of South Africa and the West African Mandinka.

"This means that modern humans emerged earlier than previously thought", says Mattias Jakobsson, population geneticist at Uppsala University who headed the project together with Stone Age archaeologist Marlize Lombard at the University of Johannesburg.

The fossil record of east Africa, and in particular the Omo and Herto fossils have often been used to set the emergence of anatomically modern humans to about 180,000 years ago. The deeper estimate for modern human divergence at 350,000-260,000 years ago coincides with the Florisbad and Hoedjiespunt fossils, contemporaries of the small-brained Homo naledi in southern Africa.

"It now seems that at least two or three Homo species occupied the southern African landscape during this time period, which also represents the early phases of the Middle Stone Age", says Marlize Lombard. It will be interesting to see in future if we find any evidence of interaction between these groups.

"We did not find any evidence of deep structure or archaic admixture among southern African Stone Age hunter-gatherers, instead, we see some evidence for deep structure in the West African population, but that affects only a small fraction of their genome and is about the same age as the deepest divergence among all humans", says Mattias Jakobsson.

The authors also found that all current-day Khoe-San populations admixed with migrant East African pastoralists a little over a thousand years ago. "We could not detect this widespread East African admixture previously since we did not have an un-admixed San group to use as reference. Now that we have access to ancient DNA of people who lived on the landscape before the East African migration, we are able to detect the admixture percentages in all San groups. The admixture percentages in the Khoekhoe, historically identified as pastoralists, are higher than previously estimated", says Carina Schlebusch.

Of the Iron Age individuals, three carry at least one Duffy null allele, protecting against malaria, and two have at least one sleeping-sickness-resistance variant in the APOL1 gene. The Stone Age individuals do not carry these protective alleles. "This tells us that Iron Age farmers carried these disease-resistance variants when they migrated to southern Africa", says co-first author Helena Malmström, archaeo-geneticist at Uppsala University.

Marlize Lombard said that "archaeological deposits dating to the time of the split by 350,000-260,000 years ago, attest to South Africa being populated by tool-making hunter-gatherers at the time.

Although human fossils are sparse, those of Florisbad and Hoedjiespunt are seen as transitional to modern humans." These fossils may therefore be ancestral to the Ballito Bay boy and other San hunter-gatherers who lived in southern Africa 2000 years ago.

The transition from archaic to modern humans might not have occurred in one place in Africa but in several, including southern Africa and northern Africa as recently reported. "Thus, both palaeo-anthropological and genetic evidence increasingly points to multiregional origins of anatomically modern humans in Africa, i.e. Homo sapiens did not originate in one place in Africa, but might have evolved from older forms in several places on the continent with gene flow between groups from different places", says Carina Schlebusch.

"It is remarkable that we can now sequence entire genomes of ancient human remains from tropical areas, such as the southeast coast of South Africa", says Helena Malmström. This is promising for our several ongoing investigations in Africa.

Cumulatively these findings shed new light on our species' deep African history and show that there is still much more to learn about our process of becoming modern humans and that the interplay between genetics and archaeology has an increasingly important role to play.

Scythians: warriors of ancient Siberia


At the British Museum this autumn (14 September 2017 – 14 January 2018), discover an ancient culture that was buried in the Siberian permafrost for thousands of years. The BP exhibition Scythians: warriors of ancient Siberia will reveal the history of these powerful nomadic tribes who thrived in a vast landscape stretching from southern Russia to China and the northern Black Sea. 

The Scythians were exceptional horsemen and warriors, and feared adversaries and neighbours of the ancient Greeks, Assyrians and Persians between 900 and 200 BC. This exhibition will tell their story through exciting archaeological discoveries and perfectly preserved objects frozen in time. This will be the first major exhibition to explore the Scythians in the UK in 40 years. 

Many of the objects on display date b ack over 2,500 years. They are exceptionally well preserved as they come from burial mounds in the high Altai mountains of southern Siberia, where the frozen ground prevented them from deteriorating. 

Over 200 outstanding objects will reveal all aspects of Scythian life, including a major loan in collaboration with the State Hermitage Museum, St Petersburg, and other generous loans from the National Museum of the Republic of Kazakhstan, the Ashmolean Museum and the Royal Collection. Some are star pieces which are displayed in the permanent galleries and Treasury of the State Hermitage Museum and others have never been loaned to the UK before. 

Objects preserved by the permafrost include multi-coloured textiles, fur-lined garments and accessories, unique horse headgear and tattooed human remains. Tattooing was common among the Scythians and incredible examples were preserved in the frozen tombs. This art shows natural and mythical animals with heavily contorted bodies, often in close combat, and we have examples of exceptionally well - preserved early tattooed remains on loan from the State Hermitage Museum.

Life in the Siberian landscape was tough and there was heavy competition for survival. The Scythians developed a fearsome set of weapons: pointed battle - axes and short swords for close combat and powerful bows for long-distance archery. Painted wooden shields, armour and a helmet have su rvived from the ancient tombs. 

The Scythians were skilled horsemen and they took their beloved horses with them to the grave so that they could carry on in the afterlife. Favourite horses were specially adorned for this and wore elaborate costumes, with masks, saddle pendants and covers for the mane and tail, which were intended to trans form them into mythical beasts.

This exhibition will explore who the Scythians were, how they appeared, what they wore, who they traded with and what they ate and drank. Perfectly preserved seeds have been found in some tombs and were part of a Scythian ritual involving the deliberate inhalation of the smoke from charred hemp. 

The fifth century BC Greek historian Herodotus described how Scythians ‘howled with pleasure’ when they inhaled the smoke and how it was employed in cleansing rituals and for pain relief. A reconstruction in the exhibition shows an ancient brazier together with the hemp seeds and the felt hood which was put over the top like a miniature tent. 

There are stunning pieces of gold jewellery, gold applique to adorn clothes, wooden drinking bowls, and a highly decorated leather bag even containing remarkably well - preserved lumps of cheese that are over 2,000 years old. There was a two - way influence between the culture of the Scythians and their settled ‘civilised ’ neighbours. 

Many objects in this exhibition show evidence of cultural interaction, from Scythian wine - drinking learnt from the ancient Greeks and Persians, through ancient Greek craftsmen who depicte d archers in Scythian dress, and the gold objects in the Achaemenid Oxus Treasure in the British Museum’s collection that are influenced by Scythian art. In about the second century BC the Scythians disappeared and were replaced by other nomadic powers. 

The exhibition concludes with an exploration of what happened afterwards and takes a look at life in southern Siberia in the early centuries AD. These objects are also spectacularly well preserved, but through extreme dryness rather than extreme cold. Haunting painted clay death masks decorated to resemble the tattooed faces of the deceased are shown alongside beautiful clothing and the reconstructed log - cabin tomb chamber in which they were discovered. 

The growing application of archaeological science is unlocking clues to the past, and new results from collaborative work by the British Museum and the State Hermitage Museum will be included in the exhibition. 

Teotihuacan: Urban Design in Ancient Central Mexico


Mighty Sun pyramid of Teotihuacan Mexico.
Credit: © schlyx / Fotolia
 
Name one civilization located in the Americas that pre-dates the arrival of Europeans. You probably replied with the Aztecs, the Inca or perhaps the Maya. A new paper, published in De Gruyter's open access journal Open Archeology, by Michael E. Smith of Arizona State University shows how this view of American civilizations is narrow. It is entitled "The Teotihuacan Anomaly: The Historical Trajectory of Urban Design in Ancient Central Mexico."

Smith, using a map produced by the Teotihuacan mapping project, conducted a comparative analysis of the city with earlier and later Mesoamerican urban centers and has proved, for the first time, the uniqueness of the city. The paper outlines how the urban design of the city of Teotihuacan differed from past and subsequent cities, only to be rediscovered and partially modelled on many centuries later by the Aztecs.

Teotihuacan was in touch with other Mesoamerican civilizations and at the height of its influence between 100 -- 650 AD, it was the largest city in the Americas, and one of the largest in the world. It is unclear who the builders of the city were, and what relation they had to the peoples which followed. It is possible they were related to the Nahua or Totonac peoples. It is also unclear why the city was abandoned. There are several theories which include foreign invasion, a civil war, an ecological catastrophe, or some combination of all three.

The Aztecs, who reached the height of their power about a thousand years later, held Teotihuacan in reverence. The site of Teotihuacan is located about forty kilometers from the site of the Aztec capital. They claimed to be the descendants of the Teotihuacans. That may or may not be true, but the Teotihuacans had a huge influence on the later Aztec culture. The name Teotihuacan comes from the Aztec language, and means 'the birthplace of the gods' and they believed it was the location of the creation of the universe. But the paper outlines how the influence of this ancient culture on the Aztecs was not limited only to their cultural beliefs, but also how it affected the urban design of their capital city, and also how unparalleled that original design was.

Most ancient cities throughout Mesoamerica followed the same planning principles, and they included the same kinds of buildings. Each city usually had a well-planned central area which included temples, a royal palace, a ballcourt, and a plaza that was surrounded by a much more chaotic (in terms of planning) residential area. Teotihuacan most likely had no royal palace, no ballcourt, and no central areas. It was much larger than cities before it, and the residential areas were much better planned than its predecessors, and it had an innovation unique in world history -- the apartment compound. Buildings with one entrance that contained many households had been rare before the industrial revolution and those that did exist were for the poor. Teotihuacan's were spacious and comfortable.

"Teotihuacan stood alone as the only city using a new and very different set of planning principles, and its apartment compounds represent a unique form of urban residence not just in Mesoamerica but in world urban history," said Michael E. Smith.

All of these features were unique in Central America before and after, until the Aztecs drew their inspiration for their capital Tenochtitlan from Teotihuacan using many of the same features.



Monday, September 25, 2017

700-year-old myth has been proven at least partly true


Scientists confirm that the age and content of an old sack is in accordance with a medieval myth about Saint Francis of Assisi.

For more than 700 years the Friary of Folloni near Montella in Italy has protected and guarded some small fragments of textile.

According to the legend the textile fragments originate from a sack that appeared on the doorstep of the friary in the winter of 1224 containing bread sent from Saint Francis of Assisi, who at that time was in France. The bread was allegedly brought to the friary by an angel.

Ever since that cold winter's night the sack has been guarded by the friary, and today the last few remaining fragments are kept as a relic in a well protected shrine.

In line with the legend

A Danish/Italian/Dutch team of reseachers led by Associate Professor Kaare Lund Rasmussen from University of Southern Denmark has had the opportunity to conduct scientific studies of the alleged bread sack fragments. Their study is published in the journal Radiocarbon.

C-14 analysis revealed that the textile can be dated to 1220-1295.

The age is in line with the legend, says Kaare Lund Rasmussen, a chemist, and specialized in archaeo-chemical analyses.

There was probably bread in the sack

The researchers also looked for traces of bread in the textile. They did this by looking for ergosterol, a sterol for the fungal kingdom and encountered in several types of mould. Ergosterol can be a potential biomarker for brewing, baking or agriculture.

The studies show that there was probably bread in the sack. We don't know when, but it seems unlikely that it was after 1732, where the sack fragments were inmured in order to protect them. It is more likely that bread was in contact with the textile in the 300 years before 1732; a period, where the textile was used as altar cloth -- or maybe it was indeed on the cold winter's night in 1224 -- it is possible, says Rasmussen.

The bread sack

According to legend the bread sack miraculously appeared on the doorstep of the friary in 1224. For 300 years it was used as an altar cloth. During this time pieces were cut off and given to other religious institutions in Italy. After an earthquake in 1732 a new friary was built and the remaining sack fragments were inmured. I 1807 the fragments were moved to the main church, Santa Maria del piano. In 1817 half of the textile was returned to the friary. In 1999 the remaining half returned. Today the fragments of the textile are kept in a reliquary.

Ancient textiles reveal differences in Mediterranean fabrics in the 1st millennium BC


IMAGE
IMAGE: Twill example from Civita Castellana, Italy, seventh century BC. view more 
Credit: Margarita Gleba
Textiles represent one of the earliest human craft technologies and applied arts, and their production would have been one of the most important time, resource and labour consuming activities in the ancient past.

In archaeological contexts, textiles are relatively rare finds, especially in Mediterranean Europe where conditions are unfavourable for organic material preservation. Many archaeological textile fragments do, however, survive in mineralised form, which forms the basis of a new study published today in Antiquity.

Detailed analysis of several hundred textile fragments has provided, for the first time, a much more detailed definition of the textile cultures in Italy and Greece during the first half of the first millennium BC.

According to Dr Margarita Gleba, the study's author and researcher at the McDonald Institute for Archaeological Research, University of Cambridge, "Luckily for us, during the Iron Age (c. 1000-400 BC) people were buried with a lot of metal goods such as personal ornaments, weapons and vessels. These metals are conducive to the preservation of textiles as the metal effectively kills off the micro-organisms which would otherwise consume the organic materials, while at the same time metal salts create casts of textile fibres, thereby preserving the textile microstructure."

"This is how we get such a large number of textiles, even though they only exist now in tiny fragments. Through meticulous analysis using digital and scanning electron microscopy, high performance liquid chromatography and other advanced methods we are able to determine a lot of information including the nature of the raw materials and structural features such as thread diameter, twist direction, type of weaving or binding, and thread count."

The technical differences suggest that during the Iron Age, textiles in Italy more closely resembled those found in Central Europe (associated with the Hallstatt culture that was prevalent in modern-day Germany, Austria and Slovenia) while the textile culture of Greece was largely connected with the Near East.

Dr Gleba added, "There is overwhelming evidence for frequent contact between Italy and Greece during the first half of the first millennium BC, but this evidence shows that their textile traditions were technically, aesthetically and conceptually very different. This means that the populations in these two regions are making an active decision to clothe themselves in a certain way and it may have to do with traditions set up already in the Bronze Age."

"Textiles have been and still are widely considered one of the most valuable indicators of individual and group identity. Even in societies today, we frequently form opinions of others based on the type of cloth they are wearing: tweed is associated with Irish and British country clothing, cashmere with Central Asia and silk with the Far East for example."

"Curiously, by Roman times, the establishment of Greek colonies in southern Italy and more general oriental influences observed in material culture of Italic populations leads towards gradual disappearance of the indigenous textile tradition. Our future research will attempt to understand the cause behind this change in textile culture."

Thursday, September 21, 2017

Ancient human DNA in sub-Saharan Africa


The first large-scale study of ancient human DNA from sub-Saharan Africa opens a long-awaited window into the identity of prehistoric populations in the region and how they moved around and replaced one another over the past 8,000 years.

The findings, published Sept. 21 in Cell by an international research team led by Harvard Medical School, answer several longstanding mysteries and uncover surprising details about sub-Saharan African ancestry -- including genetic adaptations for a hunter-gatherer lifestyle and the first glimpses of population distribution before farmers and animal herders swept across the continent about 3,000 years ago.

"The last few thousand years were an incredibly rich and formative period that is key to understanding how populations in Africa got to where they are today," said David Reich, professor of genetics at HMS and a senior associate member of the Broad Institute of MIT and Harvard. "Ancestry during this time period is such an unexplored landscape that everything we learned was new."

"Ancient DNA is the only tool we have for characterizing past genomic diversity. It teaches us things we don't know about history from archaeology and linguistics and can help us better understand present-day populations," said Pontus Skoglund, a postdoctoral researcher in the Reich lab and the study's first author. "We need to ensure we use it for the benefit of all populations around the world, perhaps especially Africa, which contains the greatest human genetic diversity in the world but has been underserved by the genomics community."

Long time coming

Although ancient-DNA research has revealed insights into the population histories of many areas of the world, delving into the deep ancestry of African groups wasn't possible until recently because genetic material degrades too rapidly in warm, humid climates.

Technological advances--including the discovery by Pinhasi and colleagues that DNA persists longer in small, dense ear bones--are now beginning to break the climate barrier. Last year, Reich and colleagues used the new techniques to generate the first genome-wide data from the earliest farmers in the Near East, who lived between 8,000 and 12,000 years ago.

In the new study, Skoglund and team, including colleagues from South Africa, Malawi, Tanzania and Kenya, coaxed DNA from the remains of 15 ancient sub-Saharan Africans. The individuals came from a variety of geographic regions and ranged in age from about 500 to 8,500 years old.

The researchers compared these ancient genomes--along with the only other known ancient genome from the region, previously published in 2015--against those of nearly 600 present-day people from 59 African populations and 300 people from 142 non-African groups.

With each analysis, revelations rolled in.

"We are peeling back the first layers of the agricultural transition south of the Sahara," said Skoglund. "Already we can see that there was a whole different landscape of populations just 2,000 or 3,000 years ago."

Genomic time-lapse

Almost half of the team's samples came from Malawi, providing a series of genomic snapshots from the same location across thousands of years.

The time-series divulged the existence of an ancient hunter-gatherer population the researchers hadn't expected.

When agriculture spread in Europe and East Asia, farmers and animal herders expanded into new areas and mixed with the hunter-gatherers who lived there. Present-day populations thus inherited DNA from both groups.

The new study found evidence for similar movement and mixing in other parts of Africa, but after farmers reached Malawi, hunter-gatherers seem to have disappeared without contributing any detectable ancestry to the people who live there today.

"It looks like there was a complete population replacement," said Reich. "We haven't seen clear evidence for an event like this anywhere else."

The Malawi snapshots also helped identify a population that spanned from the southern tip of Africa all the way to the equator about 1,400 years ago before fading away. That mysterious group shared ancestry with today's Khoe-San people in southern Africa and left a few DNA traces in people from a group of islands thousands of miles away, off the coast of Tanzania.

"It's amazing to see these populations in the DNA that don't exist anymore," said Reich. "It's clear that gathering additional DNA samples will teach us much more."

"The Khoe-San are such a genetically distinctive people, it was a surprise to find a closely related ancestor so far north just a couple of thousand years ago," Reich added.

The new study also found that West Africans can trace their lineage back to a human ancestor that may have split off from other African populations even earlier than the Khoe-San.

Missing links

The research similarly shed light on the origins of another unique group, the Hadza people of East Africa.

"They have a distinct appearance, language and genetics, and some people speculated that, like the Khoe-San, they might represent a very early diverging group from other African populations," said Reich. "Our study shows that instead, they're somehow in the middle of everything."

The Hadza, according to genomic comparisons, are today more closely related to non-Africans than to other Africans. The researchers hypothesize that the Hadza are direct descendants of the group that migrated out of Africa, and possibly spread within Africa as well, after about 50,000 years ago.
Another discovery lay in wait in East Africa.

Scientists had predicted the existence of an ancient population based on the observation that present-day people in southern Africa share ancestry with people in the Near East. The 3,000-year-old remains of a young girl in Tanzania provided the missing evidence.

Reich and colleagues suspect that the girl belonged to a herding population that contributed significant ancestry to present-day people from Ethiopia and Somalia down to South Africa. The ancient population was about one-third Eurasian, and the researchers were able to further pinpoint that ancestry to the Levant region.

"With this sample in hand, we can now say more about who these people were," said Skoglund.
The finding put one mystery to rest while raising another: Present-day people in the Horn of Africa have additional Near Eastern ancestry that can't be explained by the group to which the young girl belonged.

Natural selection

Finally, the study took a first step in using ancient DNA to understand genetic adaptation in African populations.

It required "squeezing water out of a stone" because the researchers were working with so few ancient samples, said Reich, but Skoglund was able to identify two regions of the genome that appear to have undergone natural selection in southern Africans.

One adaptation increased protection from ultraviolet radiation, which the researchers propose could be related to life in the Kalahari Desert. The other variant was located on genes related to taste buds, which the researchers point out can help people detect poisons in plants.

The researchers hope that their study encourages more investigation into the diverse genetic landscape of human populations in Africa, both past and present. Reich also said he hopes the work reminds people that African history didn't end 50,000 years ago when groups of humans began migrating into the Near East and beyond.