Ancient DNA sheds light on Arctic hunter-gatherer migration to North America ~5,000 years ago

Ancient DNA sheds light on Arctic hunter-gatherer migration to North America ~5,000 years ago

An ancient population of Arctic hunter-gatherers, known as Paleo-Eskimos, made a significant genetic contribution to populations living in Arctic North America today

New research reveals the profound impact of Arctic hunter-gathers who moved from Siberia to North America about 5000 years ago on present-day Native Americans. Although this group is well-known from archaeology and ancient DNA, previous genetic studies suggested that they may have been largely replaced by the groups that gave rise to present-day Arctic peoples such as the Inuit, Yup’ik, and Aleuts. The present study proves that many present-day North Americans derive significant heritage from this ancient population.

The first humans in North America arrived from Asia some time before 14,500 years ago. The next major stream of gene flow came about 5000 years ago, and is known to archaeologists as Paleo-Eskimos. About 800 years ago, the ancestors of the present-day Inuit and Yup'ik people replaced this population across the Arctic. By about 700 years ago, the archaeological evidence for the Paleo-Eskimo culture disappeared. Their genetic legacy in living populations has been contentious, with several genetic studies arguing that they made little contribution to later North Americans.

In the current study, researchers generated genome-wide data from 48 ancient individuals and 93 modern individuals from Siberia, Alaska, the Aleutian Islands and Canada, and compared this with previously published data. The researchers used novel analysis methods to create a comprehensive model of population history that included many ancient and modern groups to determine how they might be related to each other. "Our study is unique, not only in that it greatly expands the number of ancient genomes from this region, but because it is the first study to comprehensively describe all of these populations in one single coherent model," states Stephan Schiffels of the Max Planck Institute for the Science of Human History.

Paleo-Eskimos
An ancient population of Arctic hunter-gatherers, known as Paleo-Eskimos, made a significant genetic contribution to populations living in Arctic North America today. Credit: Illustration by Kerttu Majander, Design by Michelle O'Reilly

Paleo-Eskimos left a lasting legacy that extends across North America

The researchers were able to show that a substantial proportion of the genetic heritage of all ancient and modern American Arctic and Chukotkan populations comes from Paleo-Eskimos. This includes people speaking Eskimo-Aleut languages, such as the Yup'ik, Inuit and Aleuts, and groups speaking Na-Dene languages, such as Athabaskan and Tlingit speakers, in Canada, Alaska, and the lower 48 states of the United States.

Based on the researchers' analysis, Paleo-Eskimos interbred with people with ancestry similar to more southern Native peoples shortly after their arrival to Alaska, between 5,000 and 4,000 years ago. The ancestors of Aleutian Islanders and Athabaskans derive their genetic heritage directly from the ancient mixture between these two groups. The researchers also found that the ancestors of the Inuit and Yup'ik people crossed the Bering Strait at least three times: first as Paleo-Eskimos to Alaska, second as predecessors of the Old Bering Sea archaeological culture back to Chukotka, and third to Alaska again as bearers of the Thule culture. During their stay in Chukotka that likely lasted for more than 1000 years, Yupik and Inuit ancestors also admixed with local groups related to present-day Chukchi and local peoples from Kamchatka.

Paleo-Eskimo ancestry is particularly widespread today in Na-Dene language speakers, which includes Athabaskan and Tlingit communities from Alaska and northern Canada, the West Coast of the United States, and the southwest United States.

"For the last seven years, there has been a debate about whether Paleo-Eskimos contributed genetically to people living in North America today; our study resolves this debate and furthermore supports the theory that Paleo-Eskimos spread Na-Dene languages," explains David Reich of Harvard Medical School and the Howard Hughes Medical Institute. "One of the most striking case examples from our study is the ancient DNA we generated from the ancient Athabaskan site of Tochak McGrath in interior Alaska, where we worked in consultation with the local community to obtain data from three approximately seven hundred year old individuals. We found that these individuals, who lived after the time when the Paleo-Eskimo archaeological culture disappeared across North America, are well modeled as a mixture of the same two ancestry components as those found in Athabaskans today, and derived more than 40% of their ancestry from Paleo-Eskimos.

The excavation of the Middle Dorset individual from the Buchanan site on southeastern Victoria Island, Nunavut, Central Canadian Arctic. Credit: T. Max Friesen

A case example for how genetics can be combined with archaeology to shed new light on the past

The researchers hope that the paper will provide an example of the value of genetic data, in the context of archaeological knowledge, to resolve long-standing questions.

"Determining what happened to this population was not possible from the archaeological record alone," explains Pavel Flegontov of the University of Ostrava. "By analyzing genetic data in concert with the archaeological data, we can meaningfully improve our understanding of the prehistory of peoples of this region. We faced challenging analytical problems due to the complex sequence of gene flows that have shaped ancestries of peoples on both sides of the Bering Strait. Reconstructing this sequence of events required new modelling approaches that we hope may be useful for solving similar problems in other regions of the world."

Attu Island, Aleutian Islands, Alaska. Credit: Jason Rogers

Press release from the Max Planck Institute for the Science of Human History / Max-Planck-Instituts für Menschheitsgeschichte

 


birch bark chewing gums

Chewing gums reveal the oldest Scandinavian human DNA

Chewing gums reveal the oldest Scandinavian human DNA

birch bark chewing gums
This is an excavation of the site in the 1990's. Credit: Per Persson/Stockholm University

The first humans who settled in Scandinavia more than 10,000 years ago left their DNA behind in ancient chewing gums, which are masticated lumps made from birch bark pitch. This is shown in a new study conducted at Stockholm University and published in Communications Biology.

There are few human bones of this age, close to 10 000 years old, in Scandinavia, and not all of them have preserved enough DNA for archaeogenetic studies. In fact, the DNA from these newly examined chewing gums is the oldest human DNA sequenced from this area so far. The DNA derived from three individuals, two females and one male, creates an exciting link between material culture and human genetics.

Ancient chewing gums are as of now an alternative source for human DNA and possibly a good proxy for human bones in archaeogenetic studies. The investigated pieces come from Huseby-Klev, an early Mesolithic hunter-fisher site on the Swedish west coast. The sites excavation was done in the early 1990's, but at this time it was not possible to analyse ancient human DNA at all, let alone from non-human tissue. The masticates were made out of birch bark tar and used as glue in tool production and other types of technology during the Stone Age.

"When Per Persson and Mikael Maininen proposed to look for hunter-gatherer DNA in these chewing gums from Huseby Klev we were hesitant but really impressed that archaeologists took care during the excavations and preserved such fragile material", says Natalija Kashuba, who was affiliated to The Museum of Cultural History in Oslo when she performed the experiments in cooperation with Stockholm University.

"It took some work before the results overwhelmed us, as we understood that we stumbled into this almost 'forensic research', sequencing DNA from these mastic lumps, which were spat out at the site some 10 000 years ago!" says Natalija Kashuba. Today Natalija is a Ph.D. student at Uppsala University.

Exciting link between material culture and human genetics

The results show that, genetically, the individuals whose DNA was found share close genetic affinity to other hunter-gatherers in Sweden and to early Mesolithic populations from Ice Age Europe. However, the tools produced at the site were a part of lithic technology brought to Scandinavia from the East European Plain, modern day Russia. This scenario of a culture and genetic influx into Scandinavia from two routes was proposed in earlier studies, and these ancient chewing gums provides an exciting link directly between the tools and materials used and human genetics.

Emrah Kirdök at Stockholm University conducted the computational analyses of the DNA. "Demography analysis suggests that the genetic composition of Huseby Klev individuals show more similarity to western hunter-gatherer populations than eastern hunter-gatherers", he says.

"DNA from these ancient chewing gums have an enormous potential not only for tracing the origin and movement of peoples long time ago, but also for providing insights in their social relations, diseases and food.", says Per Persson at the Museum of Cultural History in Oslo. "Much of our history is visible in the DNA we carry with us, so we try to look for DNA where ever we believe we can find it", says Anders Götherström, at the Archaeological Research Laboratory at Stockholm University, where the work was conducted. The study is published in Communications Biology.

birch bark chewing gums
This is a masticate being examined. Credit: Natalija Kashuba/Stockholm University

Press release from Stockholm University


South American population decline populations Patagonia

Abrupt climate change drove early South American population decline

Abrupt climate change drove early South American population decline

Abrupt climate change some 8,000 years ago led to a dramatic decline in early South American populations, suggests new UCL research.

South American population decline populations Patagonia
Patagonia. Photo by Céline Harrand, Public Domain

The study, published in Scientific Reports, is the first to demonstrate how widespread the decline was and the scale at which population decline took place 8,000 to 6,000 years ago.

"Archaeologists working in South America have broadly known that some 8,200 years ago, inhabited sites in various places across the continent were suddenly abandoned. In our study we wanted to connect the dots between disparate records that span the Northern Andes, through the Amazon, to the southern tip of Patagonia and all areas in between," said lead author, Dr Philip Riris (UCL Institute of Archaeology).

"Unpredictable levels of rainfall, particularly in the tropics, appear to have had a negative impact on pre-Columbian populations until 6,000 years ago, after which recovery is evident. This recovery appears to correlate with cultural practices surrounding tropical plant management and early crop cultivation, possibly acting as buffers when wild resources were less predictable," added Dr Riris.

The study focused on the transition to the Middle Holocene (itself spanning 8,200 and 4,200 years ago), a period of particularly profound change when hunter-gatherer populations were already experimenting with different domestic plants, and forming new cultural habits to suit both landscape and climate change.

While the research shows that there was a significant disruption to population, the study highlights that indigenous people of South America were thriving before and after the middle Holocene.

Co-author, Dr Manuel Arroyo-Kalin (UCL Institute of Archaeology), said: "In the years leading up to population decline, we can see that population sizes were unharmed. This would suggest that early Holocene populations, probably with a social memory of abrupt climate change during the Pleistocene-Holocene transition, developed successful strategies to deal with climate change.

"Abandonment of certain regions and the need to adapt quickly to new circumstances may have promoted the exploration of alternative strategies and new forms of subsistence, including the early adoption of low scale cultivation of domestic plants. Viewed in the context of at least 14,000 years of human presence in South America, the events of the Middle Holocene are a key part of indigenous South Americans' cultural resilience to abrupt and unexpected change."

In this new study, archaeologists examined data from nearly 1,400 sites consisting of more than 5,000 radiocarbon dates to understand how population changed over time, and cross-referenced this information with climate data.

Dr Riris explained: "We studied ancient records of rainfall such as marine sediments for evidence of exceptional climate events. Within windows of 100 years, we compared the Middle Holocene to the prevalent patterns before and after 8,200 years ago. Normal patterns of rainfall suggest on average an unusually dry or wet year every 16-20 years, while under highly variable conditions this increases to every 5 years or so. This puts in perspective the challenge that indigenous communities would have faced."

The authors believe that the research offers crucial historical context on how ancient indigenous South American populations dealt with climate change.

Dr Arroyo-Kalin concluded: "Our study brings a demographic dimension to bear on understandings of the effects of past climate change, and the challenges that were faced by indigenous South Americans in different places. This understanding gauges the resilience of past small-scale productive systems and can potentially help shape future strategies for communities in the present."

###

The research was funded by a UCL CREDOC grant, the Sainsbury Research Unit at University of East Anglia and a British Academy Postdoctoral Fellowship at UCL.

 

 

 

Press release from University College London


Amazonia Llanos de Moxos Bolivia agriculture

Human settlements in Amazonia much older than previously thought

Human settlements in Amazonia much older than previously thought

Amazonia Llanos de Moxos Bolivia agriculture
An endless watery plain characterizes the Llanos. Picture by Sam Beebe, CC BY-SA 2.0

UNIVERSITY PARK, Pa. -- Humans settled in southwestern Amazonia and even experimented with agriculture much earlier than previously thought, according to an international team of researchers.

"We have long been aware that complex societies emerged in Llanos de Moxos in southwestern Amazonia, Bolivia, around 2,500 years ago, but our new evidence suggests that humans first settled in the region up to 10,000 years ago during the early Holocene period," said Jose Capriles, assistant professor of anthropology. "These groups of people were hunter gatherers; however, our data show that they were beginning to deplete their local resources and establish territorial behaviors, perhaps driving them to begin domesticating plants such as sweet potatoes, cassava, peanuts and chili peppers as a way to acquire food."

The archaeological team conducted its study on three forest islands -- Isla del Tesoro, La Chacra and San Pablo -- within the seasonally flooded savanna of the Llanos de Moxos in northern Bolivia.

"These islands are elevated above the surrounding savanna, so they do not flood during the rainy season," said Capriles. "We believe people were using these sites recurrently as seasonal camps, particularly during the long rainy seasons when most of the Llanos de Moxos become flooded."

The team's excavations of the forest islands revealed human skeletons that had been intentionally buried in a manner unlike that of typical hunter gatherers and instead were more akin to the behaviors of complex societies -- characterized by political hierarchy and the production of food. Their results appear today in Science Advances.

"If these were highly mobile hunter gatherers you would not expect for them to bury their dead in specific places; instead, they would leave their dead wherever they died," said Capriles.

Capriles noted that it is rare to find human or even archaeological remains that predate the use of fired pottery in the region.

"The soils tend to be very acidic, which often makes the preservation of organic remains very poor," he said. "Also, organic matter deteriorates quickly in tropical environments and this region completely lacks any type of rock for making stone tools, so even those are not available to study."

According to Umberto Lombardo, earth scientist at the University of Bern, when the researchers first published their discovery of these archaeological sites in 2013, they had to base their conclusions on indirect evidence -- mostly geochemical analyses -- rather than direct evidence such as artifacts.

"Because of the lack of direct evidence many archaeologists were skeptical about our findings," said Lombardo. "They did not really believe that those forest islands were early Holocene archaeological sites. The current study provides strong and definitive evidence of the anthropocentric origin of these sites, because the archaeological excavations uncovered early Holocene human burials. These are the definitive proof of the antiquity and origin of these sites."

Capriles noted that the human bones on these forest islands were preserved despite the poor conditions because they were encased within middens -- or trash heaps -- containing abundant fragments of shell, animal bones and other organic remains.

"These people were foraging apple snails during the wet season and disposing of the shells in large heaps, called middens," said Capriles. "Over time, water dissolved the calcium carbonate from the shells and those carbonates precipitated over the bones, effectively fossilizing them."

Because the human bones were fossilized, the team was unable to date them directly using radiocarbon dating. Instead, they used radiocarbon dating of associated charcoal and shell as a proxy for estimating the time range that the sites were occupied.

"The abundant remains of burned earth and wood suggests that the people were using fire, likely to clear land, cook food and keep warm during long rainy days," said Capriles.

According to Capriles, a gap exists between the people his team studied who lived on the forest islands between 10,000 and 4,000 years ago and the rise of complex societies, which began around 2,500 years ago.

"This paper represents the first step in the effort to learn more about the people who inhabited southwestern Amazonia for thousands of years but we know nothing about," said Lombardo.

Capriles added, "Are the people we found direct predecessors of those later, more complex societies? There are still questions to be answered and we hope to do so in future research."

Read more


From hunting to herding in the Early Neolithic settlement of Aşıklı Höyük

Switch from hunting to herding recorded in ancient pee

Urine salts reveal timing and scale of neolithic revolution at Turkish site

Study authors Jay Quade (left) and Jordan Abell (right) looking for optimal samples at the site of an ancient Turkish settlement where salts left behind by animal and human urine give clues about the development of livestock herding. Credit: Güneş Duru

The transition from hunting and gathering to farming and herding is considered a crucial turning point in the history of humanity. Scholars think the intensive food production that came along with the Neolithic Revolution, starting around 10,000 B.C., allowed cities to grow, led to technological innovation and, eventually, enabled life as we know it today.

It has been difficult to work out the details of how and when this took place. But a new study published in Science Advances begins to resolve the scale and pace of change during the first phases of animal domestication at an ancient site in Turkey. To reconstruct this history, the authors turned to an unusual source: urine salts left behind by humans and animals.

Whereas dung is commonly used in all sorts of studies, “this is the first time, to our knowledge, that people have picked up on salts in archaeological materials, and used them in a way to look at the development of animal management,” says lead author Jordan Abell, a graduate student at Columbia’s Lamont-Doherty Earth Observatory.

The team used the urine salts to calculate the density of humans and animals at the site over time, estimating that around 10,000 years ago, the density of people and animals occupying the settlement jumped from near zero to approximately one person or animal for every 10 square meters. The results suggest that domestication may have been more rapid than previously expected. They also support the idea that the Neolithic Revolution didn’t have just one birthplace in the Fertile Crescent of the Mideast, but rather occurred across several locations simultaneously.

Connecting the Dots

At the ancient settlement of Aşıklı Höyük in central Turkey, archaeological evidence suggests that humans began domesticating sheep and goats around 8450 BC. These practices evolved over the next 1,000 years, until the society became heavily dependent on the beasts for food and other materials.

Students working on the western Section of Aşıklı Höyük, where the evidence was found. Credit: Güneş Duru

As it happened, co-authors Susan Mentzer from the University of Tübingen and Jay Quade from the University of Arizona, where Abell worked on this project as an undergraduate, had previously documented some unusually high levels of salts around Aşıklı Höyük, and were perplexed by what they meant. Using this data and others, the new study supports the idea that the salts likely came from the urine of humans, sheep and goats. The study uses the abundance of the salts over time to track the growth of the community and its animals over a period of 1,000 years.

A Rapid Transition

Working with Turkish archaeologists, including Istanbul University’s Mihriban Özbaşaran, who heads the Aşıklı Höyük dig, the team collected 113 samples from all across the site — from trash piles to bricks and hearths, and from different time periods — to look at patterns in the sodium, nitrate and chlorine salt levels.

They found that, overall, the urine salts at Aşıklı Höyük increased in abundance over time. The natural layers before the settlement was built contained very low levels of salts. The oldest layers with evidence of human habitation, spanning 10,400 to 10,000 years ago, saw slight increases but remained relatively low in the urine salts. Then the salts spike during a period from 10,000 to 9,700 years ago; the amount of salts in this layer is about 1,000 times higher than in the preceding ones, indicating a rapid increase in the number of occupants (both human and animal). After that, the concentrations decrease slightly.

Abell says these trends line up with previous hypotheses based on other evidence from the site — that the settlement transitioned first from mostly hunting sheep and goats to corralling just a few, then changed to larger-scale management, and then finally shifted to keeping animals in corrals on the periphery of the site as their numbers grew. And although the timing is close to what the study authors expected, the sharp change around 10,000 years ago “may be new evidence for a more rapid transition” toward domestication, says Abell.

Using the salt concentrations, the team estimated the number and density of people plus sheep and goats at Aşıklı Höyük, after accounting for other factors that might have influenced the salt levels. They calculated that around 10,000 years ago, the density of people and animals occupying the settlement jumped from near zero to approximately one person or animal for every 10 square meters. By comparison, modern-day semi-intensive feedlots have densities of about one sheep for every 5 square meters.

Although it is not currently possible to distinguish between human and livestock urine salts, the urine salt analysis method can still provide a helpful estimate of sheep and goat abundance. Over the 1,000 year period, the team calculated that an average of 1,790 people and animals lived and peed on the settlement every day. In each time period, the estimated inhabitants were much higher than the number of people that archaeologists think the settlement’s buildings would have housed. This indicates that the urine salt concentrations can indeed reflect the relative amounts of domesticated animals over time.

Aşıklı Höyük Turkey Neolithic Revolution
View from the rooftops of reconstructed Aşıklı Höyük houses from the 8th and 9th century BC. Credit: Güneş Duru

The researchers plan to further refine their methods and calculations in the future, and hope to find a way to differentiate between human and animal urine salts. They think the methodology could be applied in other arid areas, and could be especially helpful at sites where other physical evidence, such as bones, is lacking.

A Broader Revolution

The study’s results also help shed light on the geographic spread of the Neolithic Revolution. It was once thought that farming and herding originated in the Fertile Crescent, which spans parts of modern-day Iraq, Syria, Lebanon, Israel, Egypt, Jordan and the Palestinian Territories, then spread outward from there. But mounting evidence, including today’s study, indicates that domestication and the transition to Neolithic lifestyles took place concurrently over a broad and diffuse swath of the region.

Anthropologist and co-author Mary Stiner from the University of Arizona said that the new method could help to clarify the larger picture of humanity’s relationship to animals during this transitional period. “We might find similar trends in other archaeological sites of the period in the Middle East,” she said, “but it is also possible that only a handful of long-lasting communities were forums for the evolving human-caprine relationships in any given region of the Middle East.”

Güneş Duru and Melis Uzdurum from Istanbul University were also authors on the paper.

 

Press release from the Earth Institute at the Columbia University, by Sarah Fecht

 

Urine salts provide evidence of Early Neolithic animal management

Urine salts elucidate Early Neolithic animal management at Aşıklı Höyük, Turkey

A close examination of midden soil layers at the early Neolithic site of Aşıklı Höyük in Turkey reveals that they are highly enriched in sodium, chlorine, and nitrate salts commonly found in human and goat and sheep urine, offering a distinct signal for following the management of those animals through the history of the site. The findings, along with an enriched nitrogen signal in the soil, suggest a new way for archaeologists to study the evolution of animal management at this critical point in human history, at similarly dry, thickly stratified sites that may not contain other domestication evidence such as animal bones or dung, or the presence of corrals or other animal enclosures. Jordan Abell and colleagues used several techniques to identify these soluble urine salts and to distinguish them from natural geological salt deposition at Aşıklı Höyük. The researchers found a 5-10 times increase in these salts between about 10,400 BP to 10,000 BP, and a 10-1000 times increase between 10,400 and 9,700 BP, demonstrating increasing reliance upon and eventual domestication of sheep and goats over this time. Based on these salt concentrations, Abell et al. estimate that about 1,790 humans and animals lived and urinated on the site per day for roughly 1,000 years of occupation. High soluble nitrogen levels in the trash heaps of the site are similar to those seen in modern feedlots, the researchers note.

Press release from the American Association for the Advancement of Science


Portuguese crowberry seeds Corema album Cova de les Cendres Alicante

The finding of Portuguese crowberry seeds in a cave in Alicante confirms its consumption in the Upper Palaeolithic

The finding of Portuguese crowberry seeds in a cave in Alicante confirms its consumption in the Upper Palaeolithic

Portuguese crowberry seeds Corema album Cova de les Cendres Alicante
Cristina Real, Ernestina Badal, Carmen M. Martinez and Villaverde

Carmen María Martínez, researcher at the University of Valencia, leads a study that reveals the consumption during the Upper Paleolithic of Portuguese crowberry (Corema album) fruits, which is currently endangered in the Mediterranean with a few specimens in the Serra Gelada. Published in the Quaternary Science Reviews magazine, the work on samples found in the Cova de les Cendres (Teulada-Moraira, Alicante) confirms the increase in aridity and sea level fluctuations at the time.

“This is one of the most important Palaeolithic sites on the peninsular Mediterranean façade. The excellent preservation conditions have allowed the recovery of an abundant archaeobotanical record from which light is shed on the collection of vegetables by the human groups that frequented the cavity and on the landscape they inhabited”, according to Ernestina Badal, Cristina Real, Valentín Villaverde, Dídac Roman and Carmen María Martínez, from the PREMEDOC-GIUV2015-213 research group of the Department of Prehistory, Archaeology and Ancient History. The Centre for Forest Research and Experimentation (CIEF) and the Polytechnic University of Valencia (UPV) have also participated in the work.

Hunter-gatherers who frequented the Cova de les Cendres not only collected these fruits, but also managed the vegetation and avoided using the plants from which they obtained food as fuel. Thus, no remaining charcoal from the more than 8,500 fragments analysed in the study has been documented. The Upper Paleolithic began about 35,000 years ago and is the period in which Homo sapiens sapiens arrived in Europe. It is characterised by the specialisation in hunting, the increase in the processing of plant foods and the diversification of tools.

The Portuguese crowberry fruits played a key role in human nutrition due to its high content of vitamin C, potassium, calcium and magnesium, according to the analysis carried out by the researcher in agrobiodiversity of the UPV Maria Dolores Raigón, since a diet based only on animal protein causes health problems. Its high nutritional value and the abundant presence of seeds suggest that there was a systematic collection of these fruits.

“The current distribution of this plant is limited to the coastal dunes of the peninsular Atlantic coast, but it has a single Mediterranean population of 11 individuals in the Serra Gelada (Benidorm), which is considered endangered by the Valencian Species Catalogue of Threatened Flora and it is believed that it is a relic of the existing population in the Cova de les Cendres”, highlight P. Pablo Ferrer, Inma Ferrando and Emilio Laguna from the CIEF. The causes of its disappearance point to a strong impact due to the increase in aridity during the maximum glacial period that took place some 20,000 years ago and to the destruction of its habitat due to the subsequent fluctuations in sea level.

Information on the collection of plants in Europe is scarce due to plant remains preservation problems in archaeological sites. These (coal, seeds, fruits and leaves) provide information on how humans lived at the time, the climate, how the landscape was modelled and the presence of different types of vegetation.

The data collected through archaeobotanical analysis show changes in regional biodiversity and could be useful for the design of environmental management policies and current and future biodiversity conservation strategies. According to the team, an interdisciplinary research is needed from Botany, Archaeology and other areas, working together to understand how ecosystems have changed over time, how humans have had to adapt to these changes and how their activities have altered the territory.

The Centre for Forestry Research and Experimentation (CIEF) and the Institute for the Conservation and Improvement of Valencian Agrobiodiversity of the Polytechnic University of Valencia participated in this study. It has been funded by the Universitat de València through the pre-doctoral grant Atracció del Talent, the Valencian Government with the PROMETEU program and the Ministry of Science and Innovation.

Article: C. M. Martínez-Varea et al.: «Corema album archaeobotanical remains in western Mediterranean basin. Assessing fruit consumption during Upper Palaeolithic in Cova de les Cendres (Alicante, Spain)». Quaternary Science Reviews 207 (2019) 1-12. DOI: https://doi.org/10.1016/j.quascirev.2019.01.004

 

 

Press release from Asociación RUVID / ES


barley Sweden Finland agriculture farming hunter gatherers Pitted Ware Culture

A 5,000-year-old barley grain discovered in Finland changes understanding of livelihoods

A 5,000-year-old barley grain discovered in Finland changes understanding of livelihoods

barley Sweden Finland agriculture farming hunter gatherers Pitted Ware Culture
Researchers determined the age of millennia-old barley grains using radiocarbon dating. Credit: photo by Santeri Vanhanen, CC-BY 4.0 licence

New findings reveal that hunter-gatherers took to farming already 5,000 years ago in eastern Sweden, and on the Aland Islands, located on the southwest coast of Finland

On the basis of prior research, representatives of the Pitted Ware Culture from the Stone Age have been known as hard-core sealers, or even Inuits of the Baltic Sea. Now, researchers have discovered barley and wheat grains in areas previously inhabited by this culture, leading to the conclusion that the Pitted Ware Culture adopted agriculture on a small scale.

A study carried out in cooperation with parties representing the discipline of archaeology and the Department of Chemistry at the University of Helsinki, as well as Swedish operators in the field of archaeology (The Archaeologists, a governmental consultant agency, and Arkeologikonsult, a business), found grains of barley and wheat in Pitted Ware settlements on Finland's Aland Islands and in the region of modern Stockholm.

The age of the grains was ascertained using radiocarbon dating. Based on the results, the grains originated in the period of the Pitted Ware culture, thus being approximately 4,300-5,300 years old. In addition to the cereal grains, the plant remnants found in the sites included hazelnut shells, apple seeds, tuberous roots of lesser celandine and rose hips.

The study suggests that small-scale farming was adopted by the Pitted Ware Culture by learning the trade from farmers of the Funnel Beaker Culture, the latter having expanded from continental Europe to Scandinavia.

Other archaeological artefacts are also evidence of close contact between these two cultures.

"The grains found on Aland are proof that the Pitted Ware Culture introduced cultivation to places where it had not yet been practised," says Santeri Vanhanen, a doctoral student of archaeology at the University of Helsinki.

In the study, the age of cereal grains found at the sites tagged with numbers in the map were determined with radiocarbon dating. These findings demonstrate that hunter-gatherers adopted farming on the Åland Islands on the southwestern coast of Finland and in eastern Sweden already 5,000 years ago. Credit: Santeri Vanhanen, CC-BY 4.0 licence

Cereal perhaps used to brew beer?

The 5,000-year-old barley grain found on Aland is the oldest grain of cereal ever found in Finland. The researchers also found a handful of barley and wheat grains a few hundred years younger, representing either common wheat or club wheat.

"We also dated one barley grain found in Raseborg, southern Finland. This grain and the other earliest grains found in mainland Finland date back some 3,500 years, some 1,500 years behind Aland according to current knowledge," Vanhanen explains.

In prior studies, it has been extremely difficult to demonstrate that the hunter-gatherer population would have adopted farming during recorded history, let alone in the Stone Age. Research on ancient DNA has in recent years proven that the spread of agriculture in Europe was almost exclusively down to migrants.

"We find it possible that this population, which was primarily specialised in marine hunting, continued to grow plants as the practice provided the community with social significance."

From time to time, an abundance of pig bones are found at Pitted Ware sites, even though pigs were not an important part of their daily nourishment. For instance, the bones of more than 30 pigs were found in a grave located on the island of Gotland.

"Members of the Pitted Ware culture may have held ritual feasts where pigs and cereal products were consumed. It's not inconceivable that grains might even have been used to brew beer, but the evidence is yet to be found," Vanhanen continues.

Santeri Vanhanen is a doctoral student of archaeology at the University of Helsinki. Credit: Marko Marila

Grain age determined through radiocarbon dating

The research relies primarily on archaeobotanical methodology, which helps examine plant remains preserved in archaeological sites. In this study, soil samples were collected from the sites, from which plant remains were extracted using a flotation method. The plant remains are charred; in other words, the grains and seeds have turned into carbon after having come to contact with fire.

Plant remains can be identified by examining them through a microscope and comparing them to modern plant parts. The age of individual grains can be determined with radiocarbon dating, based on the fractionation of the radioactive carbon-14 isotope. This way, the age of a grain aged several millennia can be determined with a precision of a few centuries.

###

The study was published in the Scientific Reports journal on 20 March 2019. The research article, entitled "Maritime Hunter-Gatherers Adopt Cultivation at the Farming Extreme of Northern Europe 5000 Years Ago", is freely available on the journal's website: https://www.nature.com/articles/s41598-019-41293-z

This is how the Inuit culture of the Baltic Sea was born. Read more on the University of Helsinki website: https://www.helsinki.fi/en/news/language-culture/a-5000-year-old-barley-grain-discovered-in-aland-southern-finland-turns-researchers-understanding-of-ancient-northern-livelihoods-upside-down

Press release from the University of Helsinki


farming agriculture

Food for thought: Why did we ever start farming?

Food for thought: Why did we ever start farming?

The reason that humans shifted away from hunting and gathering, and to agriculture -- a much more labor-intensive process -- has always been a riddle. It is only more confusing because the shift happened independently in about a dozen areas across the globe.

"A lot of evidence suggests domestication and agriculture doesn't make much sense," says Elic Weitzel, a Ph.D. student in UConn's department of anthropology. "Hunter-gatherers are sometimes working fewer hours a day, their health is better, and their diets are more varied, so why would anyone switch over and start farming?"

Weitzel sought to get to the root of the shift in his new paper in American Antiquity, by looking at one area of the world, the Eastern United States.In a nutshell, he looked for evidence to support either of two popular theories.

One theory posits that in times of plenty there may have been more time to start dabbling in the domestication of plants like squash and sunflowers, the latter of which were domesticated by the native peoples of Tennessee around 4,500 years ago.

The other theory argues that domestication may have happened out of need to supplement diets when times were not as good. As the human population grew, perhaps resources shifted due to reasons such as over-exploitation of resources or a changing climate. "Was there some imbalance between resources and the human populations that lead to domestication?"

Weitzel tested both hypotheses. He did this by analyzing animal bones from the last 13,000 years and taken from a half-dozen archeological sites in northern Alabama and the Tennessee River valley, where human settlements and their detritus give clues about how they lived, including what they ate. He coupled the findings with pollen data taken from sediment cores collected from lakes and wetlands, cores that serve as a record about the types of plants present at different points in time. The findings are ... mixed.

Weitzel found pollen from oak and hickory, leading to the conclusion that forests composed of those species began to dominate the region as the climate warmed, but also led to decreasing water levels in lakes and wetlands. Along with the decreasing lakes, the bone records showed a shift from diets rich in water fowl and large fishes to subsistence on smaller shellfish.

Taken together, that data provides evidence for the second hypothesis: There was some kind of imbalance between the growing human population and their resource base, effected perhaps by exploitation and also by climate change.

But Weitzel also saw support for the first hypothesis in that an abundance of oak and hickory forest supported an equally prevalent game species population. "That is what we see in the animal bone data," says Weitzel. "Fundamentally, when times are good and there are lots of animals present, you'd expect people to hunt the prey that is most efficient," says Weitzel. "Deer are much more efficient than squirrels for example, which are smaller, with less meat, and more difficult to catch."

A single deer or goose can feed several people, but if over-hunted, or if the landscape changes to one less favorable for the animal population, humans must subsist on other smaller, less efficient food sources. Agriculture, despite being hard work, may have become a necessary option to supplement diet when imbalances like these occurred.

Despite the mixed results, the findings supporting domestication happening in times when there was less than an ideal amount of food is significant, says Weitzel.

"I think that the existence of declining efficiency in even one habitat type is enough to show that ... domestication happening in times of plenty isn't the best way to understand initial domestication." The broader context of this research is important, says Weitzel, because looking to the past and seeing how these populations coped and adapted to change can help inform what we should do as today's climate warms in the coming decades.

"Having an archaeological voice backed by this deep-time perspective in policy making is very important."

farming agriculture
Image by Sasin Tipchai from Pixabay

Press release from the University of Connecticut


farmers from Anatolia hunter-gatherers Turkey agriculture

First Anatolian farmers were local hunter-gatherers that adopted agriculture

First Anatolian farmers were local hunter-gatherers that adopted agriculture

The first farmers from Anatolia, who brought farming to Europe and represent the single largest ancestral component in modern-day Europeans, are directly descended from local hunter-gatherers who adopted a farming way of life

An international team, led by scientists from the Max Planck Institute for the Science of Human History and in collaboration with scientists from the United Kingdom, Turkey and Israel, has analyzed 8 pre-historic individuals, including the first genome-wide data from a 15,000-year-old Anatolian hunter-gatherer, and found that the first Anatolian farmers were direct descendants of local hunter-gatherers. These findings provide support for archaeological evidence that farming was adopted and developed by local hunter-gatherers who changed their subsistence strategy, rather than being introduced by a large movement of people from another area. Interestingly, while the study shows the long-term persistence of the Anatolian hunter-gatherer gene pool over 7,000 years, it also indicates a pattern of genetic interactions with neighboring groups.

Farming was developed approximately 11,000 years ago in the Fertile Crescent, a region that includes present-day Iraq, Syria, Israel, Lebanon, Egypt and Jordan as well as the fringes of southern Anatolia and western Iran. By about 8,300 BCE it had spread to central Anatolia, in present-day Turkey. These early Anatolian farmers subsequently migrated throughout Europe, bringing this new subsistence strategy and their genes. Today, the single largest component of the ancestry of modern-day Europeans comes from these Anatolian farmers. It has long been debated, however, whether farming was brought to Anatolia similarly by a group of migrating farmers from the Fertile Crescent, or whether the local hunter-gatherers of Anatolia adopted farming practices from their neighbors.

A new study by an international team of scientists led by the Max Planck Institute for the Science of Human History and in collaboration with scientists from the United Kingdom, Turkey and Israel, published in Nature Communications, confirms existing archaeological evidence that shows that Anatolian hunter-gatherers did indeed adopt farming themselves, and the later Anatolian farmers were direct descendants of a gene-pool that remained relatively stable for over 7,000 years.

Local hunter-gatherers adopted an agricultural lifestyle

For this study, the researchers newly analyzed ancient DNA from 8 individuals, and succeeded in recovering for the first time whole-genome data from a 15,000-year-old Anatolian hunter-gatherer. This allowed the team to compare that individual's DNA to later Anatolian farmers, as well as individuals from neighboring regions, to determine how they were related. They also compared the individuals newly analyzed in the study to existing data from 587 ancient individuals and 254 present-day populations.

The researchers found that the early Anatolian farmers derived the vast majority of their ancestry (~90%) from a population related to the Anatolian hunter-gatherer in the study. "This suggests a long-term genetic stability in central Anatolia over five millennia, despite changes in climate and subsistence strategy," explains Michal Feldman of the Max Planck Institute for the Science of Human History.

"Our results provide additional, genetic support for previous archaeological evidence that suggests that Anatolia was not merely a stepping stone in a movement of early farmers from the Fertile Crescent into Europe," states Choongwon Jeong of the Max Planck Institute of the Science of Human History, co-senior author of the study. "Rather, it was a place where local hunter-gatherers adopted ideas, plants and technology that led to agricultural subsistence."

Genetic interactions with neighbors warrant further study

In addition to the long-term stability of the major component of the Anatolian ancestry, the researchers also found a pattern of interactions with their neighbors. By the time that farming had taken hold in Anatolia between 8,300-7,800 BCE, the researchers found that the local population had about a 10% genetic contribution from populations related to those living in what is today Iran and the neighboring Caucasus, with almost the entire remaining 90% coming from Anatolian hunter-gatherers. By about 7000-6000 BCE, however, the Anatolian farmers derived about 20% of their ancestry from populations related to those living in the Levant region.

"There are some large gaps, both in time and geography, in the genomes we currently have available for study," explains Johannes Krause of the Max Planck Institute for the Science of Human History, senior author on the study. "This makes it difficult to say how these more subtle genetic interactions took place - whether it was through short-term large movements of people, or more frequent but low-level interactions." The researchers hope that further research in this and neighboring regions could help to answer these questions.

farmers from Anatolia hunter-gatherers Turkey agriculture
This is the burial of a 15,000 year old Anatolian hunter-gatherer. Credit: Douglas Baird

Press release from the Max Planck Institute for the Science of Human History/Max-Planck-Institut für Menschheitsgeschichte (MPI-SHH)