Thursday, March 29, 2018

Archaeologist discovers Cornish barrow site

An Archaeologist at The Australian National University (ANU) has discovered a prehistoric Bronze-Age barrow, or burial mound, on a hill in Cornwall and is about to start excavating the untouched site which overlooks the English Channel.

The site dates back to around 2,000 BC and was discovered by chance when ANU Archaeologist Dr Catherine Frieman, who was conducting geophysical surveys of a known site outside the village of Looe in Cornwall, was approached by a farmer about a possible site in a neighbouring field.

"He told us about a 'lump' on his land and that nobody knew what it was, so he asked us to take a look at it," said Dr Frieman, who is a Senior Lecturer in the ANU School of Archaeology and Anthropology.

"So we ran our equipment over a 1,600 metre square area and sure enough we found a quite obvious circular ditch - about 15 metres across - with a single entrance pointing south east and a bunch of pits in the middle.

"We said 'oh my god - that's definitely a barrow'."

Dr Frieman said ancient barrows in the UK are usually always burial sites, although in Cornwall they can vary and might not contain human remains.

"We just don't know what we'll find until we start digging," she said.

"In Cornwall, human remains are only found in about half of the barrows that have been excavated, and not very many have been excavated compared to other parts of Britain."

Dr Frieman's work has overturned the accepted belief that Cornish barrows don't have ditches. She said of the surveys involving her team, 90 per cent of barrows have ditches.

Dr Frieman has arrived in Cornwall and is assembling her team. They will start excavation work on Easter Saturday and have 14 days to complete the dig.

"We want to examine the negative features that look like pits. They may be for holding up posts of a timber structure inside the ditch, or they could be pits that have small cremations in them - something you do find in Cornish barrows.

"Cremated human remains in pottery in pits can tell us all sorts of things about the people who were there."

Dr Frieman said the things put into burials was usually the most interesting. Stone tools like flint knives and ground stone axes and pottery have been recovered from nearby Cornish Barrows, but gold objects and ornaments of exotic material were also occasionally deposited in them.

"We think these coastal waters were really important for the movement of metals in the Bronze Age. Tin is a famous Cornish resource and Cornish Tin is really important to the western European Bronze Age," she said.

Dr Frieman has been able to mount the geophysical survey and excavation work with the help of Discovery Early Career Researcher Award (DECRA) and a contribution from the ANU College of Archaeology and Anthropology.

The excavations are being carried out in collaboration with the Cornwall Archaeological Society, the Cornwall Archaeological Unit, and with support from the National Trust who own and manage the site.

Wednesday, March 28, 2018

People who lived at the end of the last ice age actually carried on with life as usual




Excavating the central platform.
Credit: Image courtesy of University of Royal Holloway London
Pioneering early people who lived at the end of the last ice age actually carried on with life as usual despite plummeting temperatures, a study at a world-famous archaeological site in North Yorkshire suggests.

Leading researchers, based at Royal Holloway, University of London, and the University of York, found that a dramatic climate event with a sudden drop in average temperatures, severe enough to halt the development of woodland, had no substantial impact on human activity at Star Carr -- a middle Stone Age archaeological site dating to around 9,000 BC.

The study sheds new light on significant debate about the sensitivity of hunter-gatherer societies to environmental change.

The prehistoric community, who persevered through the cold snap that would last more than 100 years, left a plethora of worked wood, animal bones, antler headdresses and flint blades buried in layers of mud as evidence of their continued productivity and endurance.

Simon Blockley, Professor of Quaternary Science at Royal Holloway, said: "It has been argued that abrupt climatic events may have caused a crash in Mesolithic populations in Northern Britain, but our study reveals, that at least in the case of the pioneering colonisers at Star Carr, early communities were able to cope with extreme and persistent climate events.

"We found people were in fact far more affected by smaller, localised changes to their environment -- Star Carr was once the site of an extensive lake and people lived around its edge.

"Over time the lake gradually became shallower and boggier, turning into fenland which eventually forced settlers to abandon the area."

The early Holocene, the current geological epoch which started some 11,500 years ago when the glaciers began to retreat, was dominated by climatic instability characterised by extreme weather events triggered by ice-ocean interaction during the final wastage of the northern hemisphere ice sheets.

The rich archaeological record at Star Carr gave the researchers the rare opportunity to directly compare the palaeoclimate record with evidence of human activity through time in the same location.
The researchers examined human activity by looking at archaeological remains recovered from layers of wetland deposits at the edge of the extensive former lake basin in the Vale of Pickering.

They found evidence of houses, large wooden platforms built on the lake edge and large quantities of artefacts and bones preserved in the lake muds and these were radiocarbon dated. Pollen, macrofossils and isotopes taken from lake sediment cores allowed the researchers to build a high-resolution picture of the climate of the area over thousands of years.

The team identified two episodes of extreme cooling which saw average temperatures drop by more than 3 degrees in the space of a decade. The first of these events occurred very early after humans began to return to the area after the last ice age.

The evidence indicates that these conditions may have slowed down the progress and activity of a community in the nascent stages. However, the second of these events, which occurred later when the community was more established, appears to have had very little impact.

Professor Nicky Milner, senior author based at the University of York, added: "Perhaps the later, more established community at Star Carr were buffered from the effects of the second extreme cooling event -- which is likely to have caused exceptionally harsh winter conditions- by their continued access to a range of resources at the site including red deer.

"We have been working at Star Carr for about 15 years and the site has produced an incredibly rare glimpse into the world of our Mesolithic ancestors who lived at the end of the ice age, about 11,000 years ago.

"Putting this archaeological data into the context of the climate and environment is very exciting and shows that we need to keep an open mind when thinking about the effects of extreme climate on early populations."

Duncan Wilson, Historic England's Chief Executive, said: "Star Carr is one of the best-known Mesolithic sites in Europe and is unique in Britain for the quantity and range of organic remains from this period.

"We have been involved with funding and supporting fieldwork at Star Carr for over a decade, and thanks to studies like these we now have a much better understanding of people's resilience in the face of climate change 11,000 years ago."

Secrets of famous Neanderthal skeleton revealed


 
An international team of researchers, led by Dr. Asier Gomez-Olivencia of the University of the Basque Country (UPV/EHU) and including Binghamton University anthropologist Rolf Quam, has provided new insights on one of the most famous Neandertal skeletons, discovered over 100 years ago: La Ferrassie 1. Nearly all of the fractures were made post-mortem.
Credit: Binghamton University, State University of New York
An international team of researchers, led by Dr. Asier Gomez-Olivencia of the University of the Basque Country (UPV/EHU) and including Binghamton University anthropologist Rolf Quam, has provided new insights on one of the most famous Neanderthal skeletons, discovered over 100 years ago: La Ferrassie 1.

"New technological approaches are allowing anthropologists to peer even deeper into the bones of our ancestors," said Quam. "In the case of La Ferrassie 1, these approaches have made it possible to identify new fossil remains and pathological conditions of the original skeleton as well as confirm that this individual was deliberately buried.

The adult male La Ferrassie 1 Neanderthal skeleton was found in 1909 in a French cave site, along with the remains of an adult woman and several Neanderthal children. All of the skeletons were interpreted as representing intentional burials, and the finds sparked much public interest at the time regarding just how human-like the Neanderthals were. The La Ferrassie 1 skeleton, in particular, has been highly influential in Neanderthal studies since its discovery.

La Ferrassie 1 was an old man (likely over 50 years old) who suffered various broken bones during his lifetime and had ongoing respiratory issues when he died. Soon after, he was buried by other members of his group in the La Ferrassie rockshelter, which was repeatedly occupied by Neanderthals during millennia. The skeleton was found in a burial pit and has been dated to between 40,000 and 54,000 years. This skeleton is one of the most important Neanderthal individuals both for its completeness and due to the important role it has played historically in the interpretation of Neanderthal anatomy and lifeways.

Now, researchers have applied some of the latest technological approaches to reveal long-held secrets in the skeleton of this iconic individual. The bones were subjected to high resolution microCT scanning to study the internal anatomy of the skull and several of the bones. The middle ear bones (malleus, incus and stapes) were identified in the scans, held in place inside the skull by sediments from the La Ferrassie cave floor. These are the smallest bones in the human body and are often not preserved in archaeological skeletons, but it was possible to extract 3D virtual models of the bones for analysis. The ear ossicles are complete and help provide a better understanding of the range of variation of this anatomical region in Neanderthals. Several pathological conditions were also identified in the skeleton, including a fracture in the collar bone (clavicle), arthritis of the spine and mild scoliosis. Researchers also examined the archaeological materials from the original excavations and identified several new fragments of vertebrae and ribs of La Ferrassie 1.

Study of the original skeleton and analysis of the fracture pattern of the cranium and long bones relying on modern forensic criteria confirmed that nearly all of the fractures were post-mortem (i.e. after death), when the bones lost collagen and were fractured in situ due to the weight of the overlying sediments. Nevertheless, the anatomical connection between the bones was not affected, confirming the original observations made over a century ago by their discoverers, that the La Ferrassie 1 individual was deliberately buried by other members of their social group.

"This insight has figured prominently in subsequent debates, still ongoing in the field, surrounding Neanderthal cultural practices," said Quam. "The application of new technological approaches to the study of La Ferrassie 1 demonstrates that, over a century after its discovery, this iconic individual is still revealing new insights into Neanderthal anatomy and behavior."

Tuesday, March 27, 2018

Compared to nomadic communities, Silk Road cities were urban food deserts



IMAGE
IMAGE: This is a market stall in the ancient Silk Road city of Kashgar (Xinjiang, China) in 2003. view more 
Credit: Photo by Michael Frachetti , Washington University in St. Louis
Like passionate foodies who know the best places to eat in every town, Silk Road nomads may have been the gastronomic elites of the Medieval Ages, enjoying diets much more diverse than their sedentary urban counterparts, suggests a new collaborative study from Washington University in St. Louis, the Institute of Archaeology in Samarkand, Uzbekistan and Kiel University in Germany.
"Historians have long thought that urban centers along the Silk Road were cosmopolitan melting pots where culinary and cultural influences from far off places came together, but our research shows that nomadic communities were probably the real the movers and shakers of food culture," said Taylor Hermes of Kiel University, lead author of the study forthcoming in Scientific Reports and a 2007 graduate of Washington University.
Based on an isotopic analysis of human bones exhumed from ancient cemeteries across Central Asia, the study suggests that nomadic groups drew sustenance from a diverse smorgasbord of foods, whereas urban communities seemed stuck with a much more limited and perhaps monotonous menu -- a diet often heavy in locally produced cereal grains.
"The 'Silk Road' has been generally understood in terms of valuable commodities that moved great distances, but the people themselves were often left out," Hermes said. "Food patterns are an excellent way to learn about the links between culture and environment, uncovering important human experiences in this great system of connectivity."
Said Cheryl Makarewicz, an archaeology professor at Kiel and Hermes' mentor: "Pastoralists are stereotypically understood as clinging to a limited diet comprised of nothing but the meat and milk of their livestock. But, this study clearly demonstrates that Silk Road pastoralists, unlike their more urbane counterparts, accessed all kinds of wild and domesticated foodstuffs that made for a unexpectedly diverse diet."
"This study provides a unique glimpse into the important ways that nomads cross cut regional settings and likely spread new foods and even cuisine along the Silk Roads, more than a thousand years ago," said study co-author Michael Frachetti, associate professor of anthropology at Washington University.
"More specifically, this study illustrates the nuanced condition of localism and globalism that defined urban centers of the time, while highlighting the capacity of more mobile communities -- such as nomadic herders -- to be the essential fiber that fueled social networks and vectors of cultural changes," Frachetti said.
For this study, human bones exhumed at archaeological digs in Uzbekistan and Kazakhstan were transported to Kiel University in Germany, where they were analyzed by Hermes. To be thorough, he also collected previously published isotopic data for the time period to bring together a complete regional picture.
"Prior to this study, there were massive gaps in what we knew about human dietary diversity along the Silk Roads," Hermes said. "The datasets were simply not there. We were able to greatly increase the geographical coverage, especially by adding samples from Uzbekistan, where many of the important routes and population centers were located."
The study draws upon field work and museum collections as part of a longstanding scientific partnership between Washington University and the Institute of Archaeology in Samarkand, Uzbekistan.
The study's assessment of individual dietary regimens is made possible by studying the isotopic signatures in ancient human bones, allowing the researchers to unlock a trove of information about the food sources, including the proportions and types of plants and animals consumed by individuals over the last decades of life.
Stable isotope analysis is the "gold standard" for tracing ancient diets. Makarewicz, a specialist in the technique, has applied it to understanding major evolutionary transitions from hunting and gathering to agriculture in the Near East. She is starting a new interdisciplinary ERC research project exploring the spread of herding across Eurasia.
Other co-authors include Elissa Bullion, a doctoral student in anthropology at Washington University and two researchers from the Uzbek partnership: Farhod Maksudov and Samariddin Mustafokulov.
Hermes, who has worked with Frachetti on archaeological digs across Central Asia for more than a decade, used these isotopic analysis techniques on human bones recovered from about a dozen nomadic and urban burial sites dating from the 2nd to 13th centuries A.D.
The burial sites were associated with a wide range of communities, climates and geographic locations, including a recently discovered settlement high in the mountains of Uzbekistan, the Otrar Oasis in Kazakhstan and an urban complex on the lowland plains of Turkmenistan.
While previous archaeological excavations at these sites have confirmed the ancient presence of domesticated crop plants and herd animals, their importance in urban diets was unknown. Isotopic analysis, however, shows how important these foods were over the long-term.
"The advantage of studying human bones is that these tissues reflect multi-year dietary habits of an individual," Hermes said. "By measuring carbon isotope ratios, we can estimate the percentage of someone's diet that came from specific categories of plants, such as wheat and barley or millet. Millets have a very distinctive carbon isotope signature, and differing ratios of nitrogen isotopes tell us about whether someone ate a mostly plant-based diet or consumed foods from higher up on the food chain, such as meat and milk from sheep or goats."
This study discovered interesting dietary differences between urban settlements along the Silk Road, but surprisingly little dietary diversity among individuals living within these communities. Perhaps driven by the limits of local environments, food production networks or cultural mandates, most people within each urban setting had similar diets.
Diets of individual nomads within the same community were found to be much more diverse. These differences, perhaps a function of variable lifetime mobility patterns, the availability of wild or domesticated food options or personal preferences, suggest that nomadic groups were not as bound by cultural limitations that may have been imposed on urban dwellers, Hermes said.
"Nomads and urbanites had different dietary niches, and this reflects a combination of environment and cultural choices that influenced diet across the Silk Roads," Hermes said. "While many historians may have assumed that interactions along the Silk Road would have led to the homogenization of culinary practices, our study shows that this was not the case, especially for urban dwellers."
For now, Hermes, Frachetti, Makarewicz and their collaborators in Samarkand look forward to applying these isotopic techniques to new archaeological mysteries across Central Asia.
"We hope our results lead to a paradigm shift in how historical phenomena can be examined through the very people who made these cultural systems possible," Hermes said. "The results here are exciting, and while not the final word by any means, pave a new way forward in applying scientific methods to the ancient world."
"For close to 10 years our academic collaboration has yielded fascinating new discoveries in archaeology and has also fostered new international partnerships, such as the one spearheaded by Taylor Hermes, to carry out archaeological science at Kiel," Frachetti said. "This international approach is what enables us all -- as a team -- to maximize the scientific potential of our collaborative fieldwork and laboratory studies in Uzbekistan for the advancement of historical and environmental knowledge more globally."

Thursday, March 22, 2018

When the Mediteranean Sea flooded human settlements


Around 7,600 years ago, the emergence of agricultural settlements in Southeastern Europe and subsequent progress of civilization suddenly came to a standstill. This was most likely caused by an abrupt sea level rise in the northern Aegean Sea.

Researchers of the Senckenberg Biodiversity and Climate Research Centre, the Goethe University in Frankfurt and the University of Toronto have now detected evidence of this oceanographic event and an earlier sudden sea-level rise in the fossils of tiny calcifying marine algae preserved in seafloor sediments in the Aegean Sea. The impact of these events on historical societal development emphasizes the potential economic and social consequences of a future rise in sea levels due to global climate change, the researchers write in the study recently published in the journal Scientific Reports.

Originating in the Middle East, the Neolithic Age witnessed one of the most significant upheavals of civilization in human history: the transition from a culture of hunter-gatherers to an agricultural and sedentary lifestyle. During the Neolithic revolution, agricultural societies also began to spread toward Southeastern Europe. However, archeological digs show that the development of settlements temporarily declined about 7,600 years ago. Researchers from Frankfurt have now identified one of the likely causes for this.

"Approximately 7,600 years ago, the sea level must have risen abruptly in the Mediterranean regions bordering Southeastern Europe. The northern Aegean, the Marmara Sea and the Black Sea recorded an increase of more than one meter. This led to the flooding of low-lying coastal areas that would have been ideal areas for settlement", says lead author Professor Dr. Jens Herrle of the German Senckenberg Biodiversity and Climate Research Centre and Goethe University.

The new study is based on a sediment core from the ocean floor of the northern Aegean Sea, which allowed Herrle and his collaborators to reconstruct the level of salinity in this part of the Mediterranean between 11,000 and 5,000 years ago. The ocean floor is richly abundant in tiny fossils of the calcified algae species Emiliania huxleyi. Viewed up-close under a scanning electron microscope, size changes in these algae preserved a signal of the level of salinity in the surface water of the Aegean during their lifetime.

"These calcifying algae evidence two rapid decreases in the salt content, at approximately 8,400 and again 7,600 years ago, which can only be explained by the fact that a higher volume of low-saline surface water flowed from the Black Sea into the northern Aegean at these times. A prerequisite for this is a rapid rise in sea levels that would lead to an increased outflow of surface water in this direction. The source of this may have been Lake Agassiz in North America. This glacial meltwater lake was enclosed in ice and experienced a massive breach during this period, which emptied an enormous volume of water into the ocean," explains Herrle.

The new evidence supports a conclusion of extensive flooding along the edges of the northeastern Mediterranean, coinciding with two standstills in the Neolithic revolution. The earlier change in sea-level approximately 8,400 years ago highlighted by the new salinity record coincides with archeological dates suggesting that settlement on low-lying areas had already been significantly impeded by rising sea levels and the subsequent climatic changes. The renewed rise in sea levels 800 years later likely further hampered the transition to agricultural communities.

"Our results show that the timing and severity of past fluctuations in sea level has already had a significant effect on human history during its early agricultural development", explains Herrle in closing. "Due to climate change, we expect global sea levels to rise by up to one meter over the next 100 years. Millions of people could thus be displaced from coastal regions, with severe social and economic consequences."

Skilled female potters travelled around the Baltic nearly 5000 years ago


Researchers at the archaeology laboratory have determined the origin and trajectories of clay pottery from nearly 5000 years ago

IMAGE
IMAGE: These are Neolithic Corded ware pottery recovered in Southern Finland. view more 
Credit: Elisabeth Holmqvist-Sipilä
Was it the fine pottery itself, or the artisans who made it, that moved around the Baltic Sea region during the Corded Ware Culture of late Neolithic period? Are the archaeological artefacts found in Finland imported goods or were they made out of Finnish clay by artisans who had mastered the new technology? These are the questions researchers are trying to answer in the most extensive original study of archaeological ceramics ever undertaken in the Nordic countries.

Researchers mapped the arrival routes of pottery and people representing the Corded Ware Culture complex (c. 2900-2300 BCE) into the Nordic countries by identifying the areas where the pottery was made.

Corded Ware pottery was very different from earlier Stone Age pottery. It represented a new technology and style, and as a new innovation, used crushed ceramics -- or broken pottery -- mixed in with the clay.

Eastern influences fashionable in Sweden

Finland, Estonia and Sweden had at least five different manufacturing areas for Corded Ware pottery which engaged in active pottery trade across the Baltic Sea approximately 5000 years ago. Häme in Southern Finland had a manufacturing hub of Corded Ware pottery which can be described as quasi-industrial in Neolithic terms, and spread its products along the Finnish coast and into Estonia.

Traditionally, Swedish archaeologists have assumed that Corded Ware pottery arrived in Sweden from the south. However, it now seems clear that that eastern influences were particularly fashionable during the Neolithic, and both pottery and people belonging to this culture arrived first in Eastern Sweden from Finland and Estonia. This was not a one-way one-time event: There were many active contacts in all directions across the Baltic Sea during the period, shown by the fact that pottery that was manufactured in Sweden over time turn up in Finland and Estonia.

Skilled female artisans

In traditional societies it is usually women who are in charge of the pottery craft and it is also common for women to relocate upon marriage. Corded Ware burials show that females were more likely to receive pottery as burial gifts, and analyses from European cemeteries show that the women were more likely to relocate during their lifetime.

It is likely that the first Corded Ware Culture artisans to arrive at the Fenno-Baltic and Swedish coasts were women who had learned their craft at their place of birth. They would have begun to use the clay available at their new home, but they mixed it with crushed pieces of pottery they had brought with them. Perhaps this was a way to preserve the older pottery which had been made in their previous homelands, thus maintaining a symbolic connection to their families and the members of their former communities in their everyday lives.

The study posits that skilled female artisans arrived in Sweden particularly from Estonia and Finland, as both the geochemical origin and cultural links of the imported pottery indicates a connection to the region. Cultural similarities in turn link the first Corded Ware communities in Finland and Estonia to the eastern part of the Bay of Finland, present day Russia.

The exchange network also suggests that even during the Stone Age, the Baltic Sea was less an obstacle and more a connection between communities, attaching Finland to a broader European culture.

International Stone Age phenomena are inscribed in pottery

The study examined clay pottery from 24 archaeological sites in Finland, Estonia and Sweden. The goal was to determine the geochemical composition and geological origin of Corded Ware pottery, i.e., where the clay came from.

The project involved international and cross-disciplinary cooperation between the group of archaeologists from Finland, Sweden and Estonia and material physicists. Funded by the Academy of Finland, the research project was headed by Elisabeth Holmqvist-Sipilä, who works at the University of Helsinki's archaeology laboratory.

"International prehistoric phenomena may be apparent in everyday objects, such as dishware and the old pottery fragments crushed into the clay they were made with," says Holmqvist-Sipilä.
"Pottery was so important to its owner that it would be carried along on long journeys. Now, thousands of years later, when most things have turned into dust, it is these objects that tell the story of the routes taken by people and their belongings."
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The results of the research were published on 5 February 2018 in the esteemed Journal of Archaeological Science.

Fish accounted for surprisingly large part of the Stone Age diet


 


 

New research at Lund University in Sweden can now show what Stone Age people actually ate in southern Scandinavia 10 000 years ago. The importance of fish in the diet has proven to be greater than expected. So, if you want to follow a Paleo diet -- you should quite simply eat a lot of fish.

Osteologists Adam Boethius and Torbjörn Ahlström have studied the importance of various protein sources in the human diet across three millennia, from around 10 500 to 7 500 years ago. This was done by combining chemical analyses of human bones from over 80 individuals, whose skeletons are the oldest discovered in Scandinavia, with osteological analyses of animal bone material.

The study is part of a doctoral thesis that has used various methods to examine the significance of fishing for the people who settled in southern Scandinavia during the millenniums after the ice from the last ice age had melted away.

"At the Norje Sunnansund settlement, outside Sölvesborg in Sweden, you can see that just over half of the protein intake has come from fish, ten per cent from seals, and around 37 per cent from land mammals, such as wild boar and red deer, and scarcely three per cent from plants such as mushrooms, berries and nuts," says Adam Boethius. "On the island of Gotland, which did not have any land mammals apart from hares, the percentage of fish in total protein consumption was even higher at just under 60 per cent. Here, seals have replaced the land mammals and account for almost 40 per cent of the protein intake, whereas hares and vegetables account for a negligible proportion," he continues.

The study shows that fish was also a highly significant protein source on the Swedish west coast, but it seems that seals and dolphins were more important for the first pioneer settlers, and that after an initial focus on hunting aquatic mammals, fishing increased as a protein source.

Previously, the researchers believed that humans at that time had been far more involved in mobile groups of big-game hunters whose main protein intake thus should have come from herbivores such as red deer, aurochs and elk, and consequently the role of fishing was not recognised.

"The dominance of fishing is a discovery that has an enormous significance for our understanding of how people lived. Fishing is relatively stationary compared to the hunting of land mammals, which provides clear indications that settlements appeared in Scandinavia much earlier than researchers previously believed," says Adam Boethius.

The fact that researchers have often missed the significance of fishing is probably because they have not actively looked for the traces that exist. Fish bones are much smaller and more brittle than the bones of mammals, and are not as well preserved. In an excavation, fish bones are almost impossible to detect while in the ground and fine-mesh sieves must be used to find them.

The researchers found that fishing was surprisingly dominant at all the sites investigated. In the study, the individuals were divided up into those who lived in marine environments and those who lived in freshwater environments. In freshwater environments the protein intake is dominated by different types of carp fish species, perch, pike and burbot. Cod dominates in marine environments, but herring, saithe, haddock, spiny dogfish and plaice are also important species. On the other hand, migratory fish, such as eel and salmon, did not account for a large proportion of food intake.

"What's interesting is that the values from the people in the various groups do not overlap. This indicates that the groups had limited mobility and mostly lived on a local diet," says Adam Boethius.
The results also show that people become more dependent on fishing over time and that certain areas were probably more densely populated than previously thought.

"Even though fish can be caught in most lakes, there are certain places that are especially favourable. It is at these sites that the people begin to settle, creating their own territory. This probably entailed violent clashes between different groups of people, which is often reflected in the various violence-related injuries to the skeletons we find in archaeological excavations."

"The increasing importance of fish means that the land was divided up. For groups that continued to be mobile this meant the creation of no-go zones, that these groups were forced to skirt around in order to find food. In the long term this leads to increasing "costs" for foraging strategies and an increasing tendency to settle is to be expected, as it becomes the best alternative," concludes Adam Boethius.

More on the scientific model behind the findings:

Stable isotopes of the elements carbon and nitrogen are present in all parts of the human body, including the skeleton, and reflect a person's diet. By analysing these isotope signals for possible food sources and relating them to the values shown in human bone material, it is possible to deduce the diet the person in question has lived on.

In this study, the bones of the 82 oldest humans in Sweden and Denmark were used. The bones were sampled and the collagen extracted and analysed in a mass spectrometer in order to obtain the stable isotope values from carbon and nitrogen. Using Bayesian statistical modelling, these values were related to corresponding values for animals and plants, thereby providing information on the general human diet in the first millenniums after the ice receded from southern Scandinavia. 

To gain an insight into how diets vary between different places, the study also included an analysis of animal bone material from four different early Mesolithic settlements, which was put in a framework consisting of information from ethnographic hunter-gatherer-fisher populations at corresponding latitudes around the world. The results show that the water's resources dominated protein intake in both marine and fresh water environments. The results also show there are considerable local variations in the preferred species, but that fishing has been highly significant for human subsistence, and the significance of fishing appears to constantly increase.

Discovery of sophisticated 115,000-year-old bone tools in China



 
White bracket indicates the area where impact scars are present.
Credit: Doyon L, Li Z, Li H, d’Errico F (2018) Discovery of circa 115,000-year-old bone retouchers at Lingjing, Henan, China. PLoS ONE 13(3): e0194318. https://doi.org/10.1371/journal.pone.0194318
An analysis of 115,000-year-old bone tools discovered in China suggests that the toolmaking techniques mastered by prehistoric humans there were more sophisticated than previously thought.
Marks found on the excavated bone fragments show that humans living in China in the early Late Pleistocene were already familiar with the mechanical properties of bone and knew how to use them to make tools out of carved stone. These humans were neither Neanderthals nor sapiens.

This major find, in which Luc Doyon of UdeM's Department of Anthropology participated, has just been published in the scientific journal PLOS ONE.

"These artefacts represent the first instance of the use of bone as raw material to modify stone tools found at an East Asian early Late Pleistocene site,"said Doyon. "They've been found in the rest of Eurasia, Africa and the Levante, so their discovery in China is an opportunity for us to compare these artifacts on a global scale.

Until now, the oldest bone tools discovered in China dated back 35,000 years and consisted of assegai (spear) points. "Prior to this discovery, research into the technical behaviour of humans inhabiting China during this period was almost solely based on the study of tools carved from stone," said Doyon.

Three types of hammers

The seven bone fragments analyzed by Luc Doyon and his colleagues were excavated between 2005 and 2015 at the Lingjing site in central China's Henan province. The artifacts were found buried at a depth of roughly 10 metres. At the time, the site was being actively used as a water spring for animals. Prehistoric humans likely used these water supply points for killing and butchering their animal prey.

The bone fragments were dated using optically stimulated luminescence (OSL), a method widely used by geologists for dating the sediment layers in which tools are found.

Doyon explained that the researchers identified three types of bone retouchers, known as soft hammers, that were used to modify stone (or lithic) tools. The first type was weathered limb bone fragments, mainly from cervid metapodials, marginally shaped by retouching and intensively used on a single area. The second type was long limb bone flakes resulting from the dismemberment of large mammals, used for quick retouching or resharpening of stone tools. And the third type was a single specimen of an antler of an axis deer that, close to its tip, shows impact scars produced by percussing various lithic blanks.

The researchers have not yet determined which hominid species the users of these prehistoric tools belonged to, although they do know that they lived during the same period as Neanderthals and Homo sapiens. "The Lingjing site yielded two incomplete human skulls that suggest interbreeding between this species and Neanderthals," Doyon said. "But this is a hypothesis that remains to be confirmed through further investigation, such as paleogenetic studies."

More discoveries to come

The analyses that led to the identification of the bone tools were conducted by Doyon and his colleagues Francesco d'Errico (Université de Bordeaux), Li Zhanyang (Shandong University) and Li Hao (Chinese Academy of Sciences), at the Henan Provincial Institute for Cultural Relics and Archaeology.

Doyon participated in the project while working on his doctoral thesis on hunting weapons manufactured from osseous materials by the first Homo sapiens inhabiting Europe between 42,000 and 30,000 years ago. Having earned his PhD in anthropology from Université de Montréal in cotutelle with Université de Bordeaux (PhD in prehistory) in September 2017, Doyon will now pursue a postdoctoral fellowship at Shandong University to conduct further analyses on the bone tools discovered at the Lingjing site.

"We only had access to a small sample, because the initial aim of the project was to study the anthropogenic nature of the modifications present on other bone fragments, and this project is still ongoing," he said. "The osseous artifacts excavated from this site were exceptionally well-preserved and the systematic analysis of all the bone assemblages during my upcoming postdoctoral research is certain to yield more exciting discoveries."

Tuesday, March 20, 2018

Dravidian language family is approximately 4,500 years old


The Dravidian language family, varieties of which are spoken by 220 million people across South Asia, is crucial in understanding the prehistory not only of the subcontinent but of Eurasia as a whole
Max Planck Institute for the Science of Human History
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This is a map of the Dravidian languages in India, Pakistan, Afghanistan and Nepal. Languages present in the dataset used in this paper are indicated by name, with languages with long.(950+ years) literatures in bold.
Credit: Kolipakam et al. A Bayesian phylogenetic study of the Dravidian language family. Royal Society Open Science (2018).
The origin of the Dravidian language family, consisting of about 80 varieties spoken by 220 million people across southern and central India and surrounding countries, can be dated to about 4,500 years ago. This estimate is based on new linguistic analyses by an international team, including researchers from the Max Planck Institute for the Science of Human History, that used data collected first-hand from native speakers representing all previously reported Dravidian subgroups. These findings, published in Royal Society Open Science, match well with earlier linguistic and archaeological studies.
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An important group for understanding human dispersals from Africa and later large-scale migrations
South Asia, reaching from Afghanistan in the west and Bangladesh in the east, is home to at least six hundred languages belonging to six large language families, including Dravidian, Indo-European, and Sino-Tibetan. The Dravidian language family, consisting of about 80 language varieties (both languages and dialects) is today spoken by about 220 million people, mostly in southern and central India but also in surrounding countries. Its four largest languages, Kannada, Malayalam, Tamil and Telugu have literary traditions spanning centuries, of which Tamil reaches back the furthest. Along with Sanskrit, Tamil is one of the world's classical languages, but unlike Sanskrit, there is continuity between its classical and modern forms documented in inscriptions, poems, and secular and religious texts and songs.

"The study of the Dravidian languages is crucial for understanding prehistory in Eurasia, as they played a significant role in influencing other language groups," explains corresponding author Annemarie Verkerk of the Max Planck Institute for the Science of Human History. Neither the geographical origin of the Dravidian language nor its exact dispersal through time is known with certainty. The consensus of the research community is that the Dravidians are natives of the Indian subcontinent and were present prior to the arrival of the Indo-Aryans (Indo-European speakers) in India around 3,500 years ago. It is likely that the Dravidian languages were much more widespread to the west in the past than they are today.

Advanced statistical methods and hand-collected data lead to robust results
In order to examine questions about when and where the Dravidian languages developed, the researchers made a detailed investigation of the historical relationships of 20 Dravidian varieties. Study author Vishnupriya Kolipakam of the Wildlife Institute of India collected contemporary first-hand data from native speakers of a diverse sample of Dravidian languages, representing all the previously reported subgroups of Dravidian.

The researchers used advanced statistical methods to infer the age and subgrouping of the Dravidian language family at about 4,000-4,500 years old. This estimate, while in line with suggestions from previous linguistic studies, is a more robust result because it was found consistently in the majority of the different statistical models of evolution tested in this study. This age also matches well with inferences from archaeology, which have previously placed the diversification of Dravidian into North, Central, and South branches at exactly this age, coinciding with the beginnings of cultural developments evident in the archaeological record.

Future research would be needed to clarify the relationships between these branches and to examine the geographical history of the language family. "Here we have a really exciting opportunity to investigate the interactions between these people, and other cultural groups in the area such as Indo-European and Austro-Asiatic on one of the great crossroads of human prehistory," states author Simon Greenhill of the Max Planck Institute for the Science of Human History.

First Saharan farming 10,000 years ago


By analysing a prehistoric site in the Libyan desert, a team of researchers from the universities of Huddersfield, Rome and Modena & Reggio Emilia has been able to establish that people in Saharan Africa were cultivating and storing wild cereals 10,000 years ago. In addition to revelations about early agricultural practices, there could be a lesson for the future, if global warming leads to a necessity for alternative crops.

The importance of find came together through a well-established official collaboration between the University of Huddersfield and the University of Modena & Reggio Emilia.

The team has been investigating findings from an ancient rock shelter at a site named Takarkori in south-western Libya. It is desert now, but in the Holocene age, some 10,000 years ago, it was part of the "green Sahara" and wild cereals grew there. More than 200,000 seeds -- in small circular concentrations -- were discovered at Takarkori, which showed that hunter-gatherers developed an early form of agriculture by harvesting and storing crops.

But an alternative possibility was that ants, which are capable of moving seeds, had been responsible for the concentrations. Dr Stefano Vanin, the University of Huddersfield's Reader in Forensic Biology and a leading entomologist in the forensic and archaeological fields, analysed a large number of samples, now stored at the University of Modena & Reggio Emilia. His observations enabled him to demonstrate that insects were not responsible and this supports the hypothesis of human activity in collection and storage of the seeds.

The investigation at Takarkori provided the first-known evidence of storage and cultivation of cereal seeds in Africa. The site has yielded other key discoveries, including the vestiges of a basket, woven from roots, that could have been used to gather the seeds. Also, chemical analysis of pottery from the site demonstrates that cereal soup and cheese were being produced.

A new article that describes the latest findings and the lessons to be learned appears in the journal Nature Plants. Titled Plant behaviour from human imprints and the cultivation of wild cereals in Holocene Sahara, it is co-authored by Anna Maria Mercuri, Rita Fornaciari, Marina Gallinaro, Savino di Lernia and Dr Vanin.

One of the article's conclusions is that although the wild cereals, harvested by the people of the Holocene Sahara, are defined as "weeds" in modern agricultural terms, they could be an important food of the future.

"The same behaviour that allowed these plants to survive in a changing environment in a remote past makes them some of the most likely possible candidates as staple resources in a coming future of global warming. They continue to be successfully exploited and cultivated in Africa today and are attracting the interest of scientists searching for new food resources," state the authors.

Monday, March 19, 2018

Volcanic eruption influenced Iceland's conversion to Christianity


Memories of the largest lava flood in the history of Iceland, recorded in an apocalyptic medieval poem, were used to drive the island's conversion to Christianity, new research suggests.

A team of scientists and medieval historians, led by the University of Cambridge, has used information contained within ice cores and tree rings to accurately date a massive volcanic eruption, which took place soon after the island was first settled.

Having dated the eruption, the researchers found that Iceland's most celebrated medieval poem, which describes the end of the pagan gods and the coming of a new, singular god, describes the eruption and uses memories of it to stimulate the Christianisation of Iceland. The results are reported in the journal Climatic Change.

The eruption of the Eldgjá in the tenth century is known as a lava flood: a rare type of prolonged volcanic eruption in which huge flows of lava engulf the landscape, accompanied by a haze of sulphurous gases. Iceland specialises in this type of eruption - the last example occurred in 2015, and it affected air quality 1400 kilometres away in Ireland.

The Eldgjá lava flood affected southern Iceland within a century of the island's settlement by Vikings and Celts around 874, but until now the date of the eruption has been uncertain, hindering investigation of its likely impacts. It was a colossal event with around 20 cubic kilometres of lava erupted - enough to cover all of England up to the ankles.

The Cambridge-led team pinpointed the date of the eruption using ice core records from Greenland that preserve the volcanic fallout from Eldgjá. Using the clues contained within the ice cores, the researchers found that the eruption began around the spring of 939 and continued at least through the autumn of 940.

"This places the eruption squarely within the experience of the first two or three generations of Iceland's settlers," said first author Dr Clive Oppenheimer of Cambridge's Department of Geography. "Some of the first wave of migrants to Iceland, brought over as children, may well have witnessed the eruption."

Once they had a date for the Eldgjá eruption, the team then investigated its consequences. First, a haze of sulphurous dust spread across Europe, recorded as sightings of an exceptionally blood-red and weakened Sun in Irish, German and Italian chronicles from the same period.

Then the climate cooled as the dust layer reduced the amount of sunlight reaching the surface, which is evident from tree rings from across the Northern Hemisphere. The evidence contained in the tree rings suggests the eruption triggered one of the coolest summers of the last 1500 years. "In 940, summer cooling was most pronounced in Central Europe, Scandinavia, the Canadian Rockies, Alaska and Central Asia, with summer average temperatures 2°C lower," said co-author Professor Markus Stoffel from the University of Geneva's Department of Earth Sciences.

The team then looked at medieval chronicles to see how the cooling climate impacted society. "It was a massive eruption, but we were still amazed just how abundant the historical evidence is for the eruption's consequences," said co-author Dr Tim Newfield, from Georgetown University's Departments of History and Biology. "Human suffering in the wake of Eldgjá was widespread. From northern Europe to northern China, people experienced long, hard winters and severe spring-summer drought. Locust infestations and livestock mortalities occurred. Famine did not set in everywhere, but in the early 940s we read of starvation and vast mortality in parts of Germany, Iraq and China."

"The effects of the Eldgjá eruption must have been devastating for the young colony on Iceland - very likely, land was abandoned and famine severe," said co-author Professor Andy Orchard from the University of Oxford's Faculty of English. "However, there are no surviving texts from Iceland itself during this time that provide us with direct accounts of the eruption."

But Iceland's most celebrated medieval poem, Voluspá ('The prophecy of the seeress') does appear to give an impression of what the eruption was like. The poem, which can be dated as far back as 961, foretells the end of Iceland's pagan gods and the coming of a new, singular god: in other words, the conversion of Iceland to Christianity, which was formalised around the turn of the eleventh century.
Part of the poem describes a terrible eruption with fiery explosions lighting up the sky, and the Sun obscured by thick clouds of ash and steam:

"The sun starts to turn black, land sinks into sea; the bright stars scatter from the sky. Steam spurts up with what nourishes life, flame flies high against heaven itself."

The poem also depicts cold summers that would be expected after a massive eruption, and the researchers link these descriptions to the spectacle and impacts of the Eldgjá eruption, the largest in Iceland since its settlement.

The poem's apocalyptic imagery marks the fiery end to the world of the old gods. The researchers suggest that these lines in the poem may have been intended to rekindle harrowing memories of the eruption to stimulate the massive religious and cultural shift taking place in Iceland in the last decades of the tenth century.

"With a firm date for the eruption, many entries in medieval chronicles snap into place as likely consequences - sightings in Europe of an extraordinary atmospheric haze; severe winters; and cold summers, poor harvests; and food shortages," said Oppenheimer. "But most striking is the almost eyewitness style in which the eruption is depicted in Voluspá. The poem's interpretation as a prophecy of the end of the pagan gods and their replacement by the one, singular god, suggests that memories of this terrible volcanic eruption were purposefully provoked to stimulate the Christianisation of Iceland."

Earliest evidence that the Maya raised and traded dogs and other animals, probably for ceremonial use


Ashley Sharpe, an archaeologist at the Smithsonian Tropical Research Institute in Panama, and colleagues combined clues from carbon, nitrogen, oxygen and strontium isotope analysis discovering the earliest evidence that the Maya raised and traded dogs and other animals, probably for ceremonial use.

Their results are published in the Proceedings of the National Academy of Sciences during the week of March 19.

"In Asia, Africa and Europe, animal management went hand-in-hand with the development of cities," said Sharpe. "But in the Americas people may have raised animals for ceremonial purposes. The growth of cities doesn't seem to be directly tied to animal husbandry."

Sharpe found that animal trade and management began in the Preclassic Period some 2,500 years ago and intensified during the Classic Period, making it likely that organized ceremonies involving animal and human sacrifice and raising animals for food played important roles in the development of Maya civilization.

Isotopes are atoms that have the same number of protons and electrons but different numbers of neutrons and therefore have different physical properties. For example, carbon has two stable isotopes: carbon 12 with six protons and six neutrons and carbon 13 with six protons and seven neutrons. Carbon in animals' bodies comes from the plant tissues they consume directly or indirectly. Most plants use the most common type of photosynthesis to turn carbon dioxide into carbohydrates. This process leaves mostly the lighter carbon isotope, carbon 12, behind, bound up in carbohydrate molecules. Corn, sugar cane and other grasses use another type of photosynthesis that concentrates heavier, carbon 13 molecules. Nitrogen isotopes in proteins demonstrate a similar pattern.

Sharpe and colleagues analyzed the isotopes in animal remains from Ceibal, Guatemala, a Maya site with one of the longest histories of continuous occupation, and one of the earliest ceremonial sites.

Most of the bones and teeth they tested were from the Maya Middle Preclassic period (700-350 B.C.).
"The animal remains fall into two categories, those with lower carbon isotopes, indicating they were eating mostly wild plants, and those with higher isotopes, which were probably eating corn."

All of the dogs, two northern turkeys, Meleagris gallopavo, the turkey species that was eventually domesticated, and one of two large cats were probably eating corn or other animals that fed on corn, such as a peccary (wild pig).

Because people in the region often killed animals that came into gardens and areas where crops were being cultivated, it is possible that peccaries and turkeys may also have been eating crop plants, but it is likely that turkeys were managed by the end of the Classic Period.

Deer bones showed butcher marks, but they were hunted from the forest, not domesticated according to isotope analysis of bones that also had lower carbon isotopes.

One large cat and a smaller cat, probably a margay, Leopardus wiedii, had lower carbon isotopes indicating that they ate animals that fed on wild plants.

The ratio of two strontium isotopes reflects the local geology in a region. Forty-four of the 46 animals had strontium isotope ratios matching Ceibal and the surrounding southern lowlands region.

However, to Sharpe's surprise, jaw bones from two dogs excavated from deep pits at the heart of the ancient ceremonial complex had strontium isotope ratios matching drier, mountainous regions near present-day Guatemala City. "This is the first evidence from the Americas of dogs being moved around the landscape," Sharpe said. "Around 1000 A.D. there's evidence that dogs were moved out to islands in the Caribbean, but the Ceibal remains are dated at about 400 B.C." Part of the jaw bone and teeth of a big cat was found with one of the dogs in the same deposit.

"The interesting thing is that this big cat was local, but possibly not wild," Sharpe said. "Based on its tooth enamel, it had been eating a diet similar to that of the dogs since it was very young. Perhaps it was captured and raised in captivity, or it lived near villages and ate animals that were feeding on corn. We still have to look at the DNA to figure out if it was a jaguar or a puma."

Sharpe is looking forward to understanding more about the context of these finds. "The results in this publication are based on excavations we did in 2012. My colleagues at the Ceibal-Petexbatun Archaeological Project will publish additional analyses, and I'm looking forward to finding out if all of the human remains at the site are from the region."

"It's interesting to consider whether humans may have had a greater impact managing and manipulating animal species in ancient Mesoamerica than has been believed," Sharpe said. "Studies like this one are beginning to show that animals played a key role in ceremonies and demonstrations of power, which perhaps drove animal-rearing and trade."

Agriculture initiated by indigenous peoples, not Fertile Crescent migration


Small scale agricultural farming was first initiated by indigenous communities living on Turkey's Anatolian plateau, and not introduced by migrant farmers as previously thought, according to new research by the University of Liverpool.

Professor Douglas Baird and his team discovered the presence of carbonised seeds and phytoliths of wheat chaff at Boncuklu, along with agricultural weeds commonly found in early farming sites, suggesting the cultivation of crops did take place.

Additionally, nitrogen isotopes from sheep and goat bone collagen indicate very small scale experimentation with the herding of these animals.

Analysis of stone tools and ancient DNA suggests an indigenous population, rather than migrants from earlier agricultural communities within the Fertile Crescent.

Professor Baird said: "Confounding the expectations of some archaeologists that the migrant farmer brought farming to central Anatolia, our evidence shows that the site of Boncuklu was occupied by long present, local Anatolian communities who mostly hunted and gathered a wide range of wetland animals and plants, but adopted farming from areas to the south and east through exchange.

"Although used; cultivated plants, wheat, lentils and peas were not fully domesticated and contributed only a small amount to the diet of the Boncuklu community."

Project Co-Director, University of Queensland Associate Professor Andrew Fairbairn, said: "Unexpectedly, this low level food production persisted for at least five centuries.

"Archaeologists usually consider these kinds of food production systems to be short-lived and transitional, but our research suggests a stable and persistent use of crops and herd animals as a minor part of the economy for a long time.

"This does not fit existing theory."

The team contrasted Boncuklu with the nearby site of P?narba??, excavated by Professor Baird in 2003-4. Lying 30km south of Boncuklu in Karaman Province, evidence suggests these communities resisted the adoption of farming and maintained a hunter-gatherer lifestyle, showing the spread of agriculture beyond the Fertile Crescent was neither uniform nor inevitable.

Professor Baird, from the University's Department of Archaeology, Classics and Egyptology, said: "Intriguingly, while P?narba?? was abandoned and its people disappeared from the archaeological record, we believe that the way of life we see at Boncuklu contributed directly to that conducted at the slightly later Neolithic settlement, Çatalhöyük.

"Farming at Boncuklu was a relatively minor economic activity 10,000 years ago, but its adoption may have had both immediate and long-term consequences for the particular communities who committed to it."

Funded by the British Academy, the British Institute at Ankara and the Australian Research Council, the research is published in the journal Proceedings of the National Academy of Sciences of the USA (PNAS).

Thursday, March 15, 2018

Modern humans interbred with Denisovans twice in history



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This graphical abstract shows two waves of Denisovan ancestry have shaped present-day humans. 
Credit: Browning et al./Cell
Modern humans co-existed and interbred not only with Neanderthals, but also with another species of archaic humans, the mysterious Denisovans. While developing a new genome-analysis method for comparing whole genomes between modern human and Denisovan populations, researchers unexpectedly discovered two distinct episodes of Denisovan genetic intermixing, or admixing, between the two. This suggests a more diverse genetic history than previously thought between the Denisovans and modern humans.

In a paper published in Cell on March 15, scientists at the University of Washington in Seattle determined that the genomes of two groups of modern humans with Denisovan ancestry--individuals from Oceania and individuals from East Asia--are uniquely different, indicating that there were two separate episodes of Denisovan admixture.

"What was known already was that Oceanian individuals, notably Papuan individuals, have significant amounts of Denisovan ancestry," says senior author Sharon Browning, a research professor of biostatistics, University of Washington School of Public Health. The genomes of modern Papuan individuals contain approximately 5% Denisovan ancestry."

Researchers also knew Denisovan ancestry is present to a lesser degree throughout Asia. The assumption was that the ancestry in Asia was achieved through migration, coming from Oceanian populations. "But in this new work with East Asians, we find a second set of Denisovan ancestry that we do not find in the South Asians and Papuans," she says. "This Denisovan ancestry in East Asians seems to be something they acquired themselves."

After studying more than 5,600 whole-genome sequences from individuals from Europe, Asia, America, and Oceania and comparing them to the Denisovan genome, Browning and colleagues determined that the Denisovan genome is more closely related to the modern East Asian population than to modern Papuans. "We analyzed all of the genomes searching for sections of DNA that looked like they came from Denisovans," says Browning, whose team relied on genomic information from the UK10K project, the 1000 Genomes Project, and the Simons Genome Diversity Project.

"When we compared pieces of DNA from the Papuans against the Denisovan genome, many sequences were similar enough to declare a match, but some of the DNA sequences in the East Asians, notably Han Chinese, Chinese Dai, and Japanese, were a much closer match with the Denisovan," she says.

What is known about Denisovan ancestry comes from a single set of archaic human fossils found in the Altai mountains in Siberia. That individual's genome was published in 2010, and other researchers quickly identified segments of Denisovan ancestry in several modern-day populations, most significantly with individuals from Oceania but also in East and South Asians.

"The assumption is that admixing with Denisovans occurred fairly quickly after humans moved out of Africa, around 50,000 years ago, but we do not know where in terms of location," Browning says. She theorizes that perhaps the ancestors of Oceanians admixed with a southern group of Denisovans while the ancestors of East Asians admixed with a northern group.

Going forward, the researchers plan on studying more Asian populations and others throughout the world, including Native Americans and Africans. "We want to look throughout the world to see if we can find evidence of interbreeding with other archaic humans," says Browning. "There are signs that intermixing with archaic humans was occurring in Africa, but given the warmer climate no one has yet found African archaic human fossils with sufficient DNA for sequencing."

Genomic ancestry of Stone Age North Africans from Morocco discovered



An international team of researchers, led by Johannes Krause and Choongwon Jeong from the Max Planck Institute for the Science of Human History (Jena, Germany), and Abdeljalil Bouzouggar from the Institut National des Sciences de l'Archéologie et du Patrimoine (Rabat, Morocco) and including scientists from the Mohammed V University in Rabat, the Natural History Museum in London, University of Oxford, Université Mohammed Premier in Oujda and the Max Planck Institute for Evolutionary Anthropology in Leipzig, have sequenced DNA from individuals from Morocco dating to approximately 15,000 years ago, as published in Science.

This is the oldest nuclear DNA from Africa ever successfully analyzed. The individuals, dating to the Late Stone Age, had a genetic heritage that was in part similar to Near Eastern populations and in part related to sub-Saharan African populations.

North Africa is an important area in the history of the evolution of our species. The geography of North Africa also makes it an interesting area for studying how humans expanded out of Africa. It is part of the African continent, but the Sahara desert presents a substantial barrier to travel to and from southern regions. Similarly, it is part of the Mediterranean region, but in the past the sea could have presented a barrier to interaction with others as well. "A better understanding of the history of North Africa is critical to understanding the history of our species," explains co-author Saaïd Amzazi of Mohammed V University in Rabat, Morocco.

In order to address this, the team looked at a burial site in Grotte des Pigeons, near Taforalt in Morocco, associated with the Later Stone Age Iberomaurusian culture. The Iberomaurusians are believed to be the first in the area to produce finer stone tools known as microliths. "Grotte des Pigeons is a crucial site to understanding the human history of north-western Africa, since modern humans frequently inhabited this cave intensively during prolonged periods throughout the Middle and Later Stone Age," explains co-author Louise Humphrey of the Natural History Museum in London. "Around 15,000 years ago there is evidence for more intensive use of the site and the Iberomaurusians started to bury their dead at the back of the cave."

15,000-year-old nuclear DNA is the oldest recovered in Africa
The researchers analyzed DNA from nine individuals from Taforalt using advanced sequencing and analytical methods. They were able to recover mitochondrial data from seven of the individuals and genome-wide nuclear data from five of the individuals. Because of the age of the samples, at approximately 15,000 years old, and the poor preservation characteristic of the area, this is an unprecedented achievement. "This is the first and the oldest Pleistocene DNA of our species recovered in Africa," explains co-senior author Abdeljalil Bouzouggar.

"Due to challenging conditions for DNA preservation, relatively few ancient genomes have been recovered from Africa and none of them so far predate the introduction of agriculture in North Africa," explains first author Marieke van de Loosdrecht of the Max Planck Institute for the Science of Human History. "Successful genome reconstruction was possible by using specialized laboratory methods to retrieve highly degraded DNA, and relatively new analysis methods to characterize the genetic profiles of these individuals."

The researchers found two major components to the genetic heritage of the individuals. About two-thirds of their heritage is related to contemporaneous populations from the Levant and about one-third is most similar to modern sub-Saharan Africans, in particular West Africans.

As early as the Stone Age, human populations had links that stretched across continents
The high proportion of Near Eastern ancestry shows that the connection between North Africa and the Near East began much earlier than many previously thought. Although the connections between these regions have been shown in previous studies for more recent time periods, it was not generally believed that humans were interacting across these distances during the Stone Age. "Our analysis shows that North Africa and the Near East, even at this early time, were part of one region without much of a genetic barrier," explains co-senior author Choongwon Jeong.

Although the Sahara did present a physical barrier, there was also clearly interaction happening at this time. The strong connection between the Taforalt individuals and sub-Saharan populations shows that interactions across this vast desert were occurring much earlier than was previously thought. In fact, the proportion of sub-Saharan ancestry of the Taforalt individuals, one-third, is a higher percentage than found in modern populations in Morocco and many other North African populations.

Sub-Saharan heritage from a previously unknown ancient population
Though the scientists found clear markers linking the heritage in question to sub-Saharan Africa, no previously identified population has the precise combination of genetic markers that the Taforalt individuals had. While some aspects match modern Hadza hunter-gatherers from East Africa and others match modern West Africans, neither of these groups has the same combination of characteristics as the Taforalt individuals. Consequently, the researchers cannot be sure exactly where this heritage comes from. One possibility is that this heritage may come from a population that no longer exists. However, this question would need further investigation.

"Clearly, human populations were interacting much more with groups from other, more distant areas than was previously assumed," states co-senior author Johannes Krause, director of the Department of Archaeogenetics at the Max Planck Institute for the Science of Human History. "This illustrates the ability of ancient genetics to add to our understanding of human history." Further studies in this region could help to clarify more about when and how these different populations interacted and where they came from.

New evidence of early human innovation, pushing back evolutionary timeline


An international collaboration, including the Natural History Museum of Utah at the University of Utah, have discovered that early humans in eastern Africa had--by about 320,000 years ago--begun trading with distant groups, using color pigments and manufacturing more sophisticated tools than those of the Early Stone Age. These newly discovered activities approximately date to the oldest known fossil record of Homo sapiens and occur tens of thousands of years earlier than previous evidence from eastern Africa. These behaviors, which are characteristic of humans who lived during the Middle Stone Age, replaced technologies and ways of life that had been in place for hundreds of thousands of years.

Evidence for these milestones in humans' evolutionary past comes from the Olorgesailie Basin in southern Kenya, which holds an archeological record of early human life spanning more than a million years. The new discoveries, reported in three studies published March 15 in the journal Science, indicate that these behaviors emerged during a period of tremendous environmental variability in the region. As earthquakes remodeled the landscape and climate fluctuated between wet and dry conditions, technological innovation, social exchange networks and early symbolic communication would have helped early humans survive and obtain the resources they needed despite unpredictable conditions, the scientists say.

"These behavioral innovations may very well represent a response to rapid changes in the environment," said Tyler Faith, curator of archaeology at the Natural History Museum of Utah, assistant professor of anthropology at the U, and coauthor of one of the three studies. "Such a response would have helped human populations endure climatic and environmental shifts that likely contributed to the demise of many other species in the region."

To better understand how climactic instability might have influenced the ecosystems in which the early humans at Olorgesailie lived, the research team integrated data from a variety of sources to assess and reconstruct the ancient environment. Faith and collaborators analyzed large mammal fossils from the archaeological sites. The bones told a story of massive turnover in the region--most species previously common in the Olorgesailie Basin had disappeared, and were replaced by others previously unknown in the basin. Some of the new ones are familiar species found in eastern Africa today, though others--including a massive zebra--are now extinct.

The team also saw evidence of dramatic range shifts, with some animals--such as the springbok, an antelope known today only from southern Africa--appearing in the basin. The faunal evidence, together with additional geological and paleoenvironmental indicators from Olorgesailie, show that the new adaptive behaviors that define earliest Homo sapiens were associated with large-scale changes in climates, faunas, and landscapes.

Rick Potts, director of the National Museum of Natural History's Human Origins Program, is the lead author on one of the three Science publications that describe the adaptive challenges that early humans faced during this phase of evolution, to which Faith contributed. Alison Brooks, professor of anthropology at George Washington University's Center for the Advanced Study of Human Paleobiology and an associate of the museum's Human Origins Program, is lead author on the paper that focuses on the evidence of early resource exchange and use of coloring materials in the Olorgesailie Basin. A third paper, by Alan Deino at the Berkeley Geochronology Center and colleagues, details the chronology of the Middle Stone Age discoveries.

The first evidence of human life in the Olorgesailie Basin comes from about 1.2 million years ago. For hundreds of the thousands of years, people living there made and used large stone-cutting tools called handaxes. Beginning in 2002, the Human Origins Program team discovered a variety of smaller, more carefully shaped tools in the basin. Isotopic dating by Deino and collaborators revealed that the tools were surprisingly old--made between 320,000and 305,000 years ago. These tools were carefully crafted and more specialized than the large, all-purpose handaxes. While the handaxes of the earlier era were manufactured using local stones, the Smithsonian team found small stone points made of non-local obsidian at their Middle Stone Age sites.

The team also found larger, unshaped pieces of the sharp-edged volcanic stone at Olorgesailie, which has no obsidian source of its own. The diverse chemical composition of the artifacts matches that of a wide range of obsidian sources in multiple directions 15 to 55 miles away, suggesting exchange networks were in place to move the valuable stone across the ancient landscape.

The team also discovered black and red rocks--manganese and ocher--at the sites, along with evidence that the rocks had been processed for use as coloring material. "We don't know what the coloring was used on, but coloring is often taken by archeologists as the root of complex symbolic communication," Potts said. "Just as color is used today in clothing or flags to express identity, these pigments may have helped people communicate membership in alliances and maintain ties with distant groups."

Tuesday, March 13, 2018

Genetic prehistory of Iberia differs from central and northern Europe


In a multidisciplinary study published in PNAS, an international team of researchers combined archaeological, genetic and stable isotope data to encapsulate 4000 years of Iberian biomolecular prehistory.

The team analyzed human remains of 13 individuals from the north and south of Spain, including the rich archaeological site of El Portalón, which forms part of the well-known site of Atapuerca in Burgos and in itself harbors 4 millennia of Iberian prehistory. The study also involved important sites like Cueva de los Murciélagos in Andalusia, from which the genome of a 7 245 year-old Neolithic farmer was sequenced making it the oldest sequenced genome in southern Iberia representing the Neolithic Almagra Pottery Culture - the early agriculturalists of southern Spain.

Background
Prehistoric migrations have played an important role in shaping the genetic makeup of European populations. After the last glacial maximum about 20 000 years ago, Europe was inhabited by hunter-gatherer groups and two major migrations during the last 10 000 years had massive impacts on lifestyle and gene pool of European populations.

First, groups originally coming from the Middle East and Anatolia introduced farming practices to Europe during the Neolithic. Less than 5 000 years ago, herder groups from the Pontic-Caspian steppe spread over the European continent. As both of these movements originated in the east, the most western parts of the continent were last to be reached by these migrations. While archaeogenetic studies have shown that both of these migrations have replaced more than half of the gene pool in Central and Northern Europe, much less is known about the influence of these events in Iberian populations, particularly in the most southern areas such as Andalusia.

Two independent migrations spread farming practices across Europe
The first farmers mainly reached Iberia following a coastal route through the northern Mediterranean Sea. The new study demonstrates that Neolithic Iberians show genetic differences to the migrant farmers that settled in Central and Northern Europe. "This suggests that all early farmers in Iberia trace most of their ancestry to the first Neolithic people that migrated into the peninsula and that later contributions from their central European counterparts were only minor", says archaeogeneticist Cristina Valdiosera from La Trobe University in Australia, one of the lead authors of the study.

These Mediterranean route migrants show a strong genetic connection with the modern-day inhabitants of the Mediterranean island of Sardinia. "We can probably consider modern Sardinians relatively direct descendants of the people who spread farming practices across the Mediterranean region around 8 000 years ago", adds Mattias Jakobsson, population geneticist at Uppsala University, Sweden and one of the senior authors of the study.

First wave of eastern migration involved small number of individuals
Despite potential other entrances into Iberia, such as North Africa or mainland Europe, the researchers did not find substantial regional differences within Iberia. Uppsala University's Torsten Günther, population geneticist and one of the lead authors of this study, says: "While geographic differences seem minor, we do see some differences over time due to interaction and genetic exchange between groups."

The first Iberian farmers show remarkably low levels of genetic diversity, indicating that the first wave of eastern migration to establish itself on the peninsula was relatively small. Following this initial period of low diversity, the newly arrived populations grew in size and mixed with the local hunter-gatherers, rapidly increasing genetic diversity during later periods.

Low genetic impact of later/Bronze Age migrations in Iberia While recent studies have demonstrated that a massive migration of Pontic-Caspian steppe herders during the Late Neolithic/Bronze Age transition is responsible for a major population turnover in central and northern Europe, the authors report in this study that the genetic influence of this migration on contemporary southwestern Europeans, namely the prehistoric Iberians, was only minor. This confirms that the genetic history of Iberia was unique as it has mostly been influenced by the main prehistoric migration associated with the introduction of farming practices - the Neolithic Revolution.

Homogenous diet in Iberian farmers
The authors also investigated the diet of these Neolithic farmers throughout almost 4000 years corroborating that despite the significant biological interaction between culturally different groups the farming culture predominated from the very beginning and continued over time. Molecular archaeologist Colin Smith from La Trobe University, one of the senior authors, explains: "Interestingly, while we do see a substantial genetic influx of hunter-gatherer ancestry into farmers over time, the diet of these early farmers does not change. Their terrestrial diet is characteristic of farming cultures and persist temporally and geographically across the millennia".

The study illustrates the power of interdisciplinary research to understand the full complexity of European prehistory. "Overall, these results emphasize the differences between the westernmost populations and their central European counterparts and highlight the need for detailed regional studies to reveal the full complexity of prehistoric migrations", Dr. Valdiosera concludes.

Modern humans flourished through ancient supervolcano eruption 74,000 years ago




Imagine a year in Africa that summer never arrives. The sky takes on a gray hue during the day and glows red at night. Flowers do not bloom. Trees die in the winter. Large mammals like antelope become thin, starve and provide little fat to the predators (carnivores and human hunters) that depend on them. Then, this same disheartening cycle repeats itself, year after year. This is a picture of life on earth after the eruption of the super-volcano, Mount Toba in Indonesia, about 74,000 years ago. In a paper published this week in Nature, scientists show that early modern humans on the coast of South Africa thrived through this event.

An eruption a hundred times smaller than Mount Toba - that of Mount Tambora, also in Indonesia, in 1815 - is thought to have been responsible for a year without summer in 1816. The impact on the human population was dire - crop failures in Eurasia and North America, famine and mass migrations. The effect of Mount Toba, a super-volcano that dwarfs even the massive Yellowstone eruptions of the deeper past, would have had a much larger, and longer-felt, impact on people around the globe.

The scale of the ash-fall alone attests to the magnitude of the environmental disaster. Huge quantities of aerosols injected high into the atmosphere would have severely diminished sunlight - with estimates ranging from a 25 to 90 percent reduction in light. Under these conditions, plant die-off is predictable, and there is evidence of significant drying, wildfires and plant community change in East Africa just after the Toba eruption.

If Mount Tambora created such devastation over a full year - and Tambora was a hiccup compared to Toba - we can imagine a worldwide catastrophe with the Toba eruption, an event lasting several years and pushing life to the brink of extinctions.

In Indonesia, the source of the destruction would have been evident to terrified witnesses - just before they died. However, as a family of hunter-gatherers in Africa 74,000 years ago, you would have had no clue as to the reason for the sudden and devastating change in the weather. Famine sets in and the very young and old die. Your social groups are devastated, and your society is on the brink of collapse.

The effect of the Toba eruption would have certainly impacted some ecosystems more than others, possibly creating areas - called refugia - in which some human groups did better than others throughout the event. Whether or not your group lived in such a refuge would have largely depended on the type of resources available. Coastal resources, like shellfish, are highly nutritious and less susceptible to the eruption than the plants and animals of inland areas.

When the column of fire, smoke and debris blasted out the top of Mount Toba, it spewed rock, gas and tiny microscopic pieces (cryptotephra) of glass that, under a microscope, have a characteristic hook shape produced when the glass fractures across a bubble. Pumped into the atmosphere, these invisible fragments spread across the world.

Panagiotis (Takis) Karkanas, director of the Malcolm H. Wiener Laboratory for Archaeological Science, American School of Classical Studies, Greece, saw a single shard of this explosion under a microscope in a slice of archaeological sediment encased in resin.

"It was one shard particle out of millions of other mineral particles that I was investigating. But it was there, and it couldn't be anything else," says Karkanas.

The shard came from an archaeological site in a rockshelter called Pinnacle Point 5-6, on the south coast of South Africa near the town of Mossel Bay. The sediments dated to about 74,000 years ago.

"Takis and I had discussed the potential of finding the Toba shards in the sediments of our archaeological site, and with his eagle eye, he found one," explains Curtis W. Marean, project director of the Pinnacle Point excavations. Marean is the associate director of the Institute of Human Origins at Arizona State University and honorary professor at the Centre for Coastal Palaeoscience at Nelson Mandela University, South Africa.

Marean showed the shard image to Eugene Smith, a volcanologist with the University of Nevada at Las Vegas, and Smith confirmed it was a volcanic shard.

"The Pinnacle Point study brought me back to the study of glass shards from my master's thesis 40 years earlier," says Smith.

Early in the study, the team brought in expert cryptotephra scientist Christine Lane who trained graduate student Amber Ciravolo in the needed techniques. Racheal Johnsen later joined Ciravalo as lab manager and developed new techniques.

From scratch, with National Science Foundation support, they developed the Cryptotephra Laboratory for Archaeological and Geological Research, which is now involved in projects not only in Africa, but in Italy, Nevada and Utah.

Encased in that shard of volcanic glass is a distinct chemical signature, a fingerprint that scientists can use to trace to the killer eruption. In their paper in Nature, the team describes finding these shards in two archaeological sites in coastal South Africa, tracing those shards to Toba through chemical fingerprinting and documenting a continuous human occupation across the volcanic event.

"Many previous studies have tried to test the hypothesis that Toba devastated human populations," Marean notes. "But they have failed because they have been unable to present definitive evidence linking a human occupation to the exact moment of the event."

Most studies have looked at whether or not Toba caused environmental change. It did, but such studies lack the archaeological data needed to show how Toba affected humans.

The Pinnacle Point team has been at the forefront of development and application of highly advanced archaeological techniques. They measure everything on site to millimetric accuracy with a "total station," a laser-measurement device integrated to handheld computers for precise and error-free recording.

Naomi Cleghorn with the University of Texas at Arlington, recorded the Pinnacle Point samples as they were removed.

Cleghorn explains, "We collected a long column of samples - digging out a small amount of sediment from the wall of our previous excavation. Each time we collected a sample, we shot its position with the total station. We could then precisely compare the position of the sample to our excavated cultural remains - the trash ancient humans left at the site. We could also compare our cryptotephra sample position with that of samples taken for dating and environmental analyses."

In addition to understanding how Toba affected humans in this region, the study has other important implications for archaeological dating techniques. Archaeological dates at these age ranges are imprecise - 10 percent (or 1000s of years) error is typical. Toba ash-fall, however, was a very quick event that has been precisely dated. The time of shard deposition was likely about two weeks in duration - instantaneous in geological terms.

"We found the shards at two sites," explains Marean. "The Pinnacle Point rockshelter (where people lived, ate, worked and slept) and an open air site about 10 kilometers away called Vleesbaai. This latter site is where a group of people, possibly members of the same group as those at Pinnacle Point, sat in a small circle and made stone tools. Finding the shards at both sites allows us to link these two records at almost the same moment in time."

Not only that, but the shard location allows the scientists to provide an independent test of the age of the site estimated by other techniques. People lived at the Pinnacle Point 5-6 site from 90,000 to 50,000 years ago. Zenobia Jacobs with the University of Wollongong, Australia, used optically stimulated luminescence (OSL) to date 90 samples and develop a model of the age of all the layers. OSL dates the last time individual sand grains were exposed to light.

"There has been some debate over the accuracy of OSL dating, but Jacobs' age model dated the layers where we found the Toba shards to about 74,000 years ago - right on the money," says Marean. This lends very strong support to Jacobs' cutting-edge approach to OSL dating, which she has applied to sites across southern Africa and the world.

"OSL dating is the workhorse method for construction of timelines for a large part of our own history. Testing whether the clock ticks at the correct rate is important. So getting this degree of confirmation is pleasing," says Jacobs.

In the 1990s, scientists began arguing that this eruption of Mount Toba, the most powerful in the last two million years, caused a long-lived volcanic winter that may have devastated the ecosystems of the world and caused widespread population crashes, perhaps even a near-extinction event in our own lineage, a so-called bottleneck.

This study shows that along the food-rich coastline of southern Africa, people thrived through this mega-eruption, perhaps because of the uniquely rich food regime on this coastline. Now other research teams can take the new and advanced methods developed in this study and apply them to their sites elsewhere in Africa so researchers can see if this was the only population that made it through these devastating times.