Nicotine extracted from ancient dental plaque for the first time

A team of scientists including researchers from Washington State University has shown for the first time that nicotine residue can be extracted from plaque, also known as "dental calculus," on the teeth of ancient tobacco users.

This is a 1945 picture of a Yokuts Native American woman smoking a pipe
[Credit: Clifford Relander]

Their research provides a new method for determining who was consuming tobacco in the ancient world and could help trace the use of tobacco and other intoxicating plants further back into prehistory.

"The ability to identify nicotine and other plant-based drugs in ancient dental plaque could help us answer longstanding questions about the consumption of intoxicants by ancient humans," said Shannon Tushingham, a WSU assistant professor of anthropology and co-author of a new study on the research in Journal of Archaeological Science Reports. "For example, it could help us determine whether all members of society used tobacco, or only adults, or only males or females."

A new source of information

Tracing the ancient spread of tobacco in the Americas has traditionally relied on the presence of pipes, charred tobacco seeds and the analysis of hair and fecal matter. However, these items are rare in the archeological record and are hard to link to particular individuals. As a result, tobacco use has been difficult to document archeologically.

On the other hand, dental plaque adheres to the surfaces of teeth and mineralizes over time, preserving a wide range of substances that are in the mouth. It is easy to link to particular individuals because it can be removed directly from teeth.

Nevertheless, dental plaque was largely ignored by archaeologists until recently.

However, using modern and highly sensitive instrumentation, scientists have found they can detect and characterize trace amounts of a wide variety of compounds, including proteins, bacterial DNA, starch grains and other plant fibers in dental plaque.

Because nicotine is detectable in the dental plaque of contemporary smokers, Tushingham and her collaborators wanted to find out if it also preserved in plaque taken from people who lived long ago.

She and David Gang, a professor in the WSU Institute of Biological Chemistry, Korey Brownstein, a graduate student in the WSU Molecular Plant Sciences Program, and Jelmer Eerkens, an anthropologist at the University of California, Davis, collaborated with members from the Ohlone tribe in San Francisco Bay to extract plaque from the teeth of eight individuals, buried between 6,000 and 300 years ago, and analyze it for nicotine.

Using ordinary dental picks, Eerkens and his team at UC Davis extracted the dental plaque from the ancient teeth and then sent it to Tushingham and Gang's labs at WSU for analysis. The WSU researchers used liquid chromatography-mass spectrometry to test the samples for nicotine and other plant-based drugs like caffeine and atropine, a muscle-relaxant.

Among the samples they analyzed, two tested positive for nicotine, demonstrating for the first time that the drug can survive in detectable amounts in ancient plaque. One of these individuals, an adult man, was also buried with a pipe. A surprise came from the molar of an older woman, which also tested positive for nicotine.

"While we can't make any broad conclusions with this single case, her age, sex, and use of tobacco is intriguing," Eerkens said. "She was probably past child-bearing age, and likely a grandmother. This supports recent research suggesting that younger adult women in traditional societies avoid plant toxins like nicotine to protect infants from harmful biochemicals, but that older women can consume these intoxicants as needed or desired."

While the researchers did not detect evidence of any other plant-based drugs in this particular study, they believe dental plaque could be used help trace the use and spread of other intoxicants as well.

"We think a wide variety of plant-based, intoxicating chemicals could be detected in ancient dental plaque," Brownstein said. "It really opens up a lot of interesting avenues of discovery."

Author: Will Ferguson | Source: Washington State University [February 27, 2018]

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Ancient DNA reveals genetic replacement despite language continuity in the South Pacific

New genetic research reveals the complex demographic history of Vanuatu, explaining how Austronesian languages were retained throughout its history despite near-total replacement of early Austronesian-Lapita with Papuan ancestry

Young men in canoes in Northwest Malakula, Vanuatu [Credit: Russell Gray & Heidi Colleran]

The study, published in Nature Ecology & Evolution and led by a multidisciplinary research team at the Max Planck Institute for the Science of Human History (MPI-SHH) together with researchers in France, Australia, New Zealand, Germany and Vanuatu, reveals that migrations of people from the Bismarck Archipelago in Oceania to the previously settled islands of the Pacific began as early as 2,500 years ago, much earlier than previously thought. The Remote Oceanian island nation of Vanuatu is the gateway to the rest of the Pacific and understanding its demographic history is critical to uncovering that of the wider region.

The earliest inhabitants of Vanuatu, arriving about 3,000 years ago, were the Lapita peoples who spoke a form of Austronesian language and who had largely East Asian genetic ancestry. But Vanuatu's contemporary population has largely Near Oceanian heritage, showing that over time the genetic ancestry of the early inhabitants was mostly replaced by that of Bismarck Archipelago migrants, who began arriving very soon after initial settlement. Yet the original Austronesian language persisted and over 120 descendant languages continue to be spoken today, making Vanuatu the per capita most linguistically diverse place on Earth.

Vanuatu therefore presents an unprecedented case, where a population's genetic ancestry but not its languages were replaced. Through analyses of new ancient and modern genome-wide data, the researchers show that rather than occurring in one wave, the genetic replacement was long and complex, likely the result of a sustained long-distance contact between Near and Remote Oceania. This provides demographic support for a model from historical linguistics, in which the initial Austronesian language of Vanuatu survived by being continually adopted by incoming Papuan migrants.

The Austronesian Expansion, which began around 5,500 years ago likely in modern-day Taiwan, was the most geographically extensive dispersal of farming peoples in prehistory, ultimately carrying people as far west as Madagascar and all the way east to Rapa Nui. These seafaring Neolithic people initially expanded out across Island Southeast Asia, carrying farming technology and a major branch of the Austronesian language family, eventually reaching Near Oceania where they encountered the indigenous Papuan peoples of New Guinea and the Bismarck Archipelago.

Dr. Frédérique Valentin excavating at Uripiv Island, Malakula, Vanuatu [Credit: Stuart Bedford]

The initial settlement east beyond the Solomon Islands and out into Remote Oceania only began around 3,000 years ago, with Austronesian-speaking groups associated with the Lapita pottery culture rapidly expanding east out to Vanuatu, New Caledonia, Fiji and the islands of Western Polynesia. A previous ancient DNA study of Lapita burial sites has shown that these earliest inhabitants had East Asian ancestry with negligible evidence of Papuan genetic admixture. But the present-day genetic make-up of Remote Oceania suggests at least some degree of Papuan ancestry, meaning there must have been subsequent Papuan migration and admixture into the Pacific from Near Oceania.

In order to understand this previously undescribed migration, a multidisciplinary team of researchers brought together different lines of evidence from the fields of genetics, archaeology and linguistics. They generated genome-wide data from the bones and teeth of 19 ancient individuals from across Vanuatu, Tonga, French Polynesia and the Solomon Islands, a significant addition to the ancient DNA record in a region whose environmental conditions generally leads to poor ancient DNA preservation.

As co-lead author Kathrin Nägele of the MPI-SHH says, "The identification of the petrous bone, which has recently been shown to provide fantastic aDNA preservation, has been a real game changer for such regions that were previously considered to be almost inaccessible." The ancient DNA was complemented by new contemporary genome-wide data from 27 present-day inhabitants of Vanuatu, collected as part of a long-term linguistic and anthropological fieldwork project run by co-authors Professor Russell Gray and Dr. Heidi Colleran of the MPI-SHH.

The ancient DNA provided direct evidence that Papuan people began arriving in Vanuatu soon after initial settlement by Austronesians. "We found a genetically Papuan-related individual dating to around 2,500 years ago in Vanuatu, far earlier than had been previously estimated using only modern genetic data," explains co-lead author Dr. Cosimo Posth, also of the MPI-SHH. The researchers were able to show that the ancestry of the initial Austronesian inhabitants of Vanuatu has been largely replaced by ancestry from Papuan peoples coming from the Bismarck Archipelago.

Maps showing the migrations in the area, including, in the final map, the migrations
 revealed by the current study [Credit: Hans Sell, adapted from Skoglund et al. Genomic
insights into the peopling of the Southwest Pacific. Nature (2016)]

But this genetic replacement was not straightforward, as Dr. Posth says, "Our analyses show that this replacement did not occur in a one-time mass migration event but rather happened incrementally over time, suggesting an enduring long-distance network between groups in Near and Remote Oceania." The authors also directly described ancient individuals with sex-biased admixture, where Papuan males intermixed with Austronesian women, as long assumed based on analyses of the modern genetic make-up of the South Pacific.

Yet despite this genetic replacement, the people of present-day Vanuatu continue to speak languages descended from those spoken by the initial Austronesian inhabitants rather than any Papuan language of the incoming migrants. As Professor Gray, Director of the Department of Linguistic and Cultural Evolution at the MPI-SHH, says, "Population replacement with language continuity is extremely rare -- if not unprecedented -- in human history.

The linguist Bob Blust has long argued for a model in which a separate Papuan expansion reaches Vanuatu soon after initial Austronesian settlement, with the initial, and likely undifferentiated, Austronesian language surviving as a lingua franca for diverse Papuan migrant groups." Dr. Adam Powell, senior author of the study and also of the MPI-SHH, continues, "The demographic history suggested by our ancient DNA analyses provides really strong support for this historical linguistic model, with the early arrival and complex, incremental process of genetic replacement by people from the Bismarck Archipelago. This provides a compelling explanation for the continuity of Austronesian languages despite the almost complete replacement of the initial genetic ancestry of Vanuatu."

The study in particular highlights the importance of interdisciplinary work and the value that multiple lines of evidence can have in deepening our understanding of human history. As Professor Johannes Krause, a senior author and Director of the Department of Archaeogenetics at the MPI-SHH, explains, "This multidisciplinary work has begun to uncover the complex, localized demographic processes that drove the initial colonization of the wider South Pacific and formed the enduring cultural and linguistic spheres that continue to shape the Pacific today." Ongoing engagement with local communities in Vanuatu, as well as with the Vanuatu Cultural Center, has been critical to this success.

As Dr. Colleran points out, "One strength of this study is the degree to which we are collaborating with communities in Vanuatu who have a real stake in these results and who generously volunteered their data to help answer these questions. We will be back in the field very soon to share the results with those communities and to hear their thoughts on the whole process." The progress of this continuing fieldwork can be followed on the Nature Ecology & Evolution Community website.

Source: Max Planck Institute for the Science of Human History [February 27, 2018]

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Ancient DNA study reveals the prehistory of Southeastern Europe

In an ancient DNA study published this week in the journal Nature, scientists and archaeologists from over 80 different institutions lift the veil on the genomic history of Southeastern Europe, a region from which very little ancient genetic data has been available until now. This is the second-largest ancient DNA study ever reported. (The largest, reported simultaneously in Nature by many of the same authors, focuses on the prehistory of Northwestern Europe.)

The burial fields of Varna, Bulgaria, is famous for its rich burial gifts. In one of the 6,500 year old graves more gold was
found than in all other graves at this time. Genetic examinations show that the DNA of the man buried there had similiarities
with the DNA of earlier European famers [Credit: © I, Yelkrokoyade, commons.wikimedia.org, CC BY-SA 3.0]

Starting around 8,500 years ago, agriculture spread into Europe from the southeast, accompanied by a movement of people from Anatolia. This study reports data from the genomes of 225 ancient people who lived both before and after this transition, and documents the interaction and mixing of these two genetically different groups of people. “Southeastern Europe was the beachhead in the spread of farming from Anatolia into Europe. This study is the first to provide a rich genetic characterization of this process by showing how the indigenous population interacted with incoming Asian immigrants at this extraordinary moment in the past,” says Songül Alpaslan-Roodenberg, a consulting anthropologist at Harvard Medical School, who identified and sampled many of the skeletons.

“In some places, hunter-gatherers and incoming farmers seem to have mixed very quickly,” says first author Iain Mathieson, a geneticist at the University of Pennsylvania, “but mostly the two groups remained isolated, at least for the first few hundred years. These hunter-gatherers had been living there for thousands of years, and it must have been quite a shock to have these new people show up—with a completely different lifestyle and appearance.”

“Three thousand years later, they were thoroughly mixed,” continues David Reich of Harvard Medical School, the Broad Institute of MIT and Harvard and the Howard Hughes Medical Institute, who co-directed the study. “Some populations derived up to a quarter of their ancestry from hunter-gatherers.” In other parts of Europe, this mixing was marked by a so-called sex bias, with most of the hunter-gatherer ancestry contributed by men. In the southeast, however, the pattern was different. “This shows that the mode of interaction between the two groups was different in different places, something we need to try to understand in the context of the archaeological evidence,” added Mathieson.

The new paper also dramatically increases the number of samples from the population of hunter-gatherers that inhabited Europe before the farmers. The study reports a particularly rich sampling of forty hunter-gatherers and early farmers from six archaeological sites from the Iron Gates region, which straddles the border of present-day Romania and Serbia. The genetic results show that the region witnessed intensive interaction between hunter-gatherers and farmers. Out of four individuals from the site of Lepenski Vir, for example, two had entirely Anatolian farmer-related ancestry, fitting with isotope evidence that they were migrants from outside the Iron Gates region, while a third individual had a mixture of ancestries and consumed aquatic resources, as expected if farmers were being integrated into hunter-gatherer groups or were adopting a hunter-gatherer lifestyle.

“These results reveal the relationship between migrations, admixture and subsistence in the this key region and show that even within early European farmers, individuals differed in their ancestry, reflecting a dynamic mosaic of hunter-farmer interbreeding,” adds Ron Pinhasi, an anthropologist at the University for Vienna, who co-directed the study.

The new paper also reports ancient DNA from the people who lived at iconic archaeological sites such as Varna, one of the first places in the world where there is evidence of extreme wealth inequality, with one individual from whom the study obtained data buried with more gold than all other known burials of the period. “The DNA from the famous Varna burial is genetically similar to that of other early European farmers. However, we also find one individual from Varna and several individuals at neighboring sites in Bulgaria who had ancestry from the eastern European steppe. This is the earliest evidence of steppe ancestry this far west—two thousand years before the mass migration from the steppe that replaced more than half of the population of northern Europe,” says Johannes Krause, Director of the Department of Archaeogenetics at the Max Planck Institute for the Science of Human History, who led the work on Varna.

Adds Reich, “These very large ancient DNA studies, involving intense collaboration between geneticists and archaeologists, make it possible to build up a rich picture of key periods of the past that could only be weakly glimpsed before. Studies on this scale represent a coming of age for the field of ancient DNA—I look forward to what we will learn when similar approaches are applied elsewhere in the world.”

Source: Max-Planck-Gesellschaft [February 23, 2018]

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Giant handaxes suggest that different groups of early humans coexisted in ancient Europe

Even our earliest human ancestors made and used technology - something we can look back on thanks to the lasting nature of stone tools.

Researchers work on the archaeological site in Spain, known as Porto Maior, where the tool deposits were found
[Credit: Eduardo Méndez Quintas, Author provided]

An exceptionally high density of giant handaxes dated to 200,000-300,000 years ago has been uncovered at an archaeological site in Galicia, northwest Spain. The findings are documented in a new article published by our international research team of archaeologists and dating specialists.

The discovery of these handaxes suggests that alternative types of stone tool technologies were simultaneously being used by different populations in this area – supporting the idea that a prehistoric “Game of Thrones” scenario existed as Neanderthals emerged in Europe.

Additional evidence for this idea comes from fossil records showing that multiple human lineages lived in southwest Europe around the same time period.

Stone tool technology

Porto Maior is near the town of As Neves (Pontevedra, Galcia) on a terrace 34m above the current level of the Miño River, which borders northern Portugal and Spain.

The large tools are consistent with a culture known as Acheulean
[Credit: Eduardo Mendez Quintas, Author provided]

The archaeological site at Porto Maior preserves an ancient stone tool culture known as the Acheulean. Characterised by symmetrically knapped stones or large flakes (known as bifaces), the Acheulean is the first sophisticated handaxe technology known in the early human settlement record of Europe.

While Acheulean sites are widespread across the continent, Porto Maior represents Europe’s first extensive accumulation of large cutting tools (LCTs) in the Acheulean tradition. Until now, such high densities of LCTs had only been found in Africa. This new finding reinforces an African origin for the Acheulean in Europe, and confirms an overlap in time-frames of distinctly different stone tool cultures on the continent.

Handaxe from Porto Maior PM4 level by Eduardo Mendez-Quintas on Sketchfab

At around the same time that handaxes were being used at Porto Maior, a different stone tool tradition (the Early Middle Palaeolithic) was present in Iberia, for example at Ambrona and Cuesta de la Bajada. In central and eastern Europe – where tools were made exclusively on small flakes – the Acheulean tradition has never been found.

Porto Maior introduces further complexity to this overlapping technological pattern, and suggests that distinct early human populations of different geographical origins coexisted during the Middle Pleistocene (between 773,000 and 125,000 years ago).

Abundant large cutting tools

In total, 3,698 discarded artefacts were recovered from river-lain sediments at the site, with 290 of these making up the studied assemblage reported in our new paper.

The stone tool assemblage is composed of 101 LCTs in original position, and that are on average 18cm long, with a maximum length of 27cm. These handaxe dimensions are exceptionally large by European Acheulean standards (typically only 8-15cm long). The assemblage also contains large cleavers, a type of tool typically found in African sites.

The Porto Maior acheulian site by Eduardo Mendez-Quintas on Sketchfab

At 9.5 pieces per m² in an excavated area of more than 11.8m², the density of the Acheulean stone tool accumulation is one of the highest recorded globally, surpassing previous European findings of smaller Acheulean tools (usually less than 3 artefacts per m²).

Laboratory analyses indicate that the tools were used to process hard materials such wood and bone, in activities that could have included the breaking up of carcasses.

The Spanish site of Porto Maior clearly resembles extensive accumulations of very large tools previously only seen in Africa and the Near East. These similarities reinforce the idea of an African origin for the Acheulean tradition of southwest Europe.

They also raise new questions regarding the origin and mobility of prehistoric human populations – the ancestors of Neanderthals – that occupied the European continent during the Middle Pleistocene period before the arrival of our own species, Homo sapiens.

Dating the tools

The age of these unusually large Acheulean tools at Porto Maior was determined using two different dating methods – post-infrared infrared stimulated luminescence (pIR-IRSL) dating of potassium feldspar grains and electron spin resonance (ESR) dating of quartz grains.

Luminescence dating samples being measured under controlled lighting conditions at the University of Adelaide’s
Prescott Environmental Luminescence Laboratory [Credit: Lee Arnold]

These techniques provide an estimate of the last time sand grains within sediments were exposed to sunlight, by looking at their luminescence or paramagnetic properties – that is, they can tell us the timing of sediment burial. This, in turn, can be used to determine when the site was last occupied and when the artefacts discarded by prehistoric populations were subsequently buried by sediment accumulation.

In the study of Porto Maior, pIR-IRSL and ESR dating were applied to grains that had been carefully collected from the sediment layers hosting the stone tools, without exposing the sample material to daylight.

The two methods, which were applied independently at two different Australian institutions (University of Adelaide and Griffith University), produced remarkably similar ages.

This confirms the reliability of the dating results, and indicates that the archaeological record spanned the time period from 200,000 to 300,000 years ago.

Migration from Africa

The Acheulean tool-making tradition originated in Africa about 1.7 million years ago, and disappeared on that continent by 500,000 years ago. The specific type of Acheulean tools described at Porto Maior is exclusive to southwest Europe, suggesting that the technology was brought into the region by an “intrusive” population.

Acheulean tools in their primary position at Porto Maior, Spain
[Credit: Eduardo Mendez-Quintas, CC BY]

The age of Porto Maior is consistent with previous findings from Iberia that suggest that the Acheulean culture experienced an expansion in the region between 400,000 to 200,000 years ago.

This latest discovery supports the increasingly complex narrative developing from ongoing studies of human fossils from Europe; namely that human groups of potentially different origins and evolutionary stages coexisted across the continent during a time when the emergence of Neanderthals was taking place.

While it is clear that more human fossil and stone tool sites need to be reliably dated across the region, a picture appears to be emerging of a turbulent “Game of Thrones” style scenario of hominin evolution in Eurasia during the Middle Pleistocene period.

Authors: Martina Demuro, Lee Arnold And Mathieu Duval | Source: The Conversation [February 23, 2018]

This article was originally published on The Conversation. Read the original article.

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Neanderthals were artistic like modern humans, study indicates

Scientists have found the first major evidence that Neanderthals, rather than modern humans, created the world's oldest known cave paintings -- suggesting they may have had an artistic sense similar to our own.

Panel 3 in Maltravieso Cave showing 3 hand stencils (centre right, centre top and top left). One has been dated to at least
66,000 years ago and must have been made by a Neanderthal (colour enhanced) [Credit: H. Collado]

A new study led by the University of Southampton and the Max Planck Institute for Evolutionary Anthropology shows that paintings in three caves in Spain were created more than 64,000 years ago -- 20,000 years before modern humans arrived in Europe.

This means that the Palaeolithic (Ice Age) cave art -- including pictures of animals, dots and geometric signs -- must have been made by Neanderthals, a 'sister' species to Homo sapiens, and Europe's sole human inhabitants at the time.

It also indicates that they thought symbolically, like modern humans.

Published in the journal Science, the study reveals how an international team of scientists used a state-of-the-art technique called uranium-thorium dating to fix the age of the paintings as more than 64,000 years.

Until now, cave art has been attributed entirely to modern humans, as claims to a possible Neanderthal origin have been hampered by imprecise dating techniques. However, uranium-thorium dating provides much more reliable results than methods such as radiocarbon dating, which can give false age estimates.

Panel 78 in La Pasiega. The scalariform (ladder shape) composed of red horizontal
and vertical lines dates to older than 64,000 years and was made by Neanderthals
[Credit: C.D Standish, A.W.G. Pike and D.L. Hoffmann]

The uranium-thorium method involves dating tiny carbonate deposits that have built up on top of the cave paintings. These contain traces of the radioactive elements uranium and thorium, which indicate when the deposits formed -- and therefore give a minimum age for whatever lies beneath.

Joint lead author Dr Chris Standish, an archaeologist at the University of Southampton, said: "This is an incredibly exciting discovery which suggests Neanderthals were much more sophisticated than is popularly believed.

"Our results show that the paintings we dated are, by far, the oldest known cave art in the world, and were created at least 20,000 years before modern humans arrived in Europe from Africa -- therefore they must have been painted by Neanderthals."

A team of researchers from the UK, Germany, Spain and France analysed more than 60 carbonate samples from three cave sites in Spain -- La Pasiega (north-eastern Spain), Maltravieso (western Spain) and Ardales (south-western Spain).

The ladder shape composed of red horizontal and vertical lines (centre left) dates to older than 64,000 years
and was made by Neanderthals [Credit: © P. Saura]

All three caves contain red (ochre) or black paintings of groups of animals, dots and geometric signs, as well as hand stencils, hand prints and engravings.

According to the researchers, creating the art must have involved such sophisticated behaviour as the choosing of a location, planning of light source and mixing of pigments.

Alistair Pike, Professor of Archaeological Sciences at the University of Southampton and co-director of the study, said: "Soon after the discovery of the first of their fossils in the 19th century, Neanderthals were portrayed as brutish and uncultured, incapable of art and symbolic behaviour, and some of these views persist today.

"The issue of just how human-like Neanderthals behaved is a hotly debated issue. Our findings will make a significant contribution to that debate."

Joint lead author Dirk Hoffmann, of the Max Planck Institute for Evolutionary Anthropology, added that symbolic material culture -- a collection of cultural and intellectual achievements handed down from generation to generation -- has, until now, only been attributed to our species.

Drawing of Panel 78 in La Pasiega by Breuil et al (1913). The red scalariform (ladder) symbol
has a minimum age of 64,000 years but it is unclear if the animals and other symbols
were painted later [Credit: Breuil et al.]

"The emergence of symbolic material culture represents a fundamental threshold in the evolution of humankind. It is one of the main pillars of what makes us human," he said.

"Artefacts whose functional value lies not so much in their practical but rather in their symbolic use are proxies for fundamental aspects of human cognition as we know it."

Early symbolic artefacts, dating back 70,000 years, have been found in Africa but are associated with modern humans.

Other artefacts including cave art, sculpted figures, decorated bone tools and jewellery have been found in Europe, dating back 40,000 years. But researchers have concluded that these artefacts must have been created by modern humans who were spreading across Europe after their arrival from Africa.

There is evidence that Neanderthals in Europe used body ornamentation around 40,000 to 45,000 years ago, but many researchers have suggested this was inspired by modern humans who at the time had just arrived in Europe.

Study co-author Paul Pettitt, of Durham University, commented: "Neanderthals created meaningful symbols in meaningful places. The art is not a one-off accident.

"We have examples in three caves 700km apart, and evidence that it was a long-lived tradition. It is quite possible that similar cave art in other caves in Western Europe is of Neanderthal origin as well."

Source: University of Southampton [February 22, 2018]

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Largest ever genomic study shows that first Beaker expansion was one of cultural diffusion

Prehistoric Iberians 'exported' their culture throughout Europe, reaching Great Britain, Sicily, Poland and all over central Europe in general. However, they did not export their genes. The Beaker culture, which probably originated in Iberia, left remains in those parts of the continent.

Iberian beakers [Credit: Museo de Almeria]

However, that diffusion was not due to large migrations of populations that took this culture with them. These are the conclusions of an international study in which the Spanish National Research Council (CSIC) was involved. Its findings, published in the journal Nature, indicate no evidence of any genetic outflow from Iberia to those areas has been discovered.

"Therefore, the diffusion of the Beaker culture from Iberia is the first example of a culture being transmitted as an idea, basically due to a question of social prestige (since it was associated with the virtues of being virile and of being warriors), which is why it is adopted by other populations," indicates researcher Carles Lalueza-Fox, from the Institute of Evolutionary Biology, a mixed research centre run by CSIC and the Pompeu Fabra University, in Barcelona, Spain.

Between 4,700 and 4,400 years ago, a new type of bell-shaped beaker pottery was introduced throughout western and central Europe. For more than a century, archaeologists have been trying to determine whether the spread of this beaker pottery -- and the (Beaker) culture associated with it -- represented a large-scale migration or whether it was due simply to the exchange of new ideas.

Now, this new study, which includes DNA data from 400 prehistoric skeletons collected from sites across Europe, resolves the debate of whether the spread was due to migrations or ideas, indicating that both arguments are correct. The findings show that the culture which produced these bell-shaped beakers extended from Iberia to central Europe without a significant movement of populations, although the Beaker culture would spread to other places through migrations at a later date.

The study, whose first author is the Spanish researcher Inigo Olalde, a geneticist at Harvard Medical School, shows that once the (Bell) Beaker culture reaches the centre of Europe (around Germany and its surrounding area), it expands backwards to other places, notably to the British Isles. Yet, in this case, it does represent a migration, replacing around 90% of the population with it.

"That is to say, the Neolithic people who built Stonehenge (and who had a greater genetic similarity with Neolithic Iberians than with those from Central Europe) almost disappear and are replaced by the populations from the Beaker culture from the Netherlands and Germany. This replacement is almost absolute in terms of the Y chromosome, which is transmitted by the paternal line, indicating an extreme reproductive bias, and therefore a previously unheard of social dominance. The backward flow also reaches other places such as Italy (at least in the north) and Iberia. I believe it is possible that this is also associated with the expansion of the Celtic or Proto-Celtic languages," Mr. Lalueza-Fox points out.

Coordinated by researcher David Reich from Harvard University, the study was developed by an international team of 144 archaeologists and geneticists from institutions in Europe and the United States.

Source: Spanish National Research Council [February 21, 2018]

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Did humans speak through cave art? New paper links ancient drawings and language’s origins

When and where did humans develop language? To find out, look deep inside caves, suggests an MIT professor.

Stock image of a cave painting in South Africa [Credit: MIT]

More precisely, some specific features of cave art may provide clues about how our symbolic, multifaceted language capabilities evolved, according to a new paper co-authored by MIT linguist Shigeru Miyagawa.

A key to this idea is that cave art is often located in acoustic “hot spots,” where sound echoes strongly, as some scholars have observed. Those drawings are located in deeper, harder-to-access parts of caves, indicating that acoustics was a principal reason for the placement of drawings within caves. The drawings, in turn, may represent the sounds that early humans generated in those spots.

In the new paper, this convergence of sound and drawing is what the authors call a “cross-modality information transfer,” a convergence of auditory information and visual art that, the authors write, “allowed early humans to enhance their ability to convey symbolic thinking.” The combination of sounds and images is one of the things that characterizes human language today, along with its symbolic aspect and its ability to generate infinite new sentences.

“Cave art was part of the package deal in terms of how homo sapiens came to have this very high-level cognitive processing,” says Miyagawa, a professor of linguistics and the Kochi-Manjiro Professor of Japanese Language and Culture at MIT. “You have this very concrete cognitive process that converts an acoustic signal into some mental representation and externalizes it as a visual.”

Cave artists were thus not just early-day Monets, drawing impressions of the outdoors at their leisure. Rather, they may have been engaged in a process of communication.

“I think it’s very clear that these artists were talking to one another,” Miyagawa says. “It’s a communal effort.”

The paper, “Cross-modality information transfer: A hypothesis about the relationship among prehistoric cave paintings, symbolic thinking, and the emergence of language,” is published in the journal Frontiers in Psychology. The authors are Miyagawa; Cora Lesure, a PhD student in MIT’s Department of Linguistics; and Vitor A. Nobrega, a PhD student in linguistics at the University of Sao Paulo, in Brazil.

Re-enactments and rituals?

The advent of language in human history is unclear. Our species is estimated to be about 200,000 years old. Human language is often considered to be at least 100,000 years old.

“It’s very difficult to try to understand how human language itself appeared in evolution,” Miyagawa says, noting that “we don’t know 99.9999 percent of what was going on back then.” However, he adds, “There’s this idea that language doesn’t fossilize, and it’s true, but maybe in these artifacts [cave drawings], we can see some of the beginnings of homo sapiens as symbolic beings.”

While the world’s best-known cave art exists in France and Spain, examples of it abound throughout the world. One form of cave art suggestive of symbolic thinking — geometric engravings on pieces of ochre, from the Blombos Cave in southern Africa — has been estimated to be at least 70,000 years old. Such symbolic art indicates a cognitive capacity that humans took with them to the rest of the world.

“Cave art is everywhere,” Miyagawa says. “Every major continent inhabited by homo sapiens has cave art. … You find it in Europe, in the Middle East, in Asia, everywhere, just like human language.” In recent years, for instance, scholars have catalogued Indonesian cave art they believe to be roughly 40,000 years old, older than the best-known examples of European cave art.

But what exactly was going on in caves where people made noise and rendered things on walls? Some scholars have suggested that acoustic “hot spots” in caves were used to make noises that replicate hoofbeats, for instance; some 90 percent of cave drawings involve hoofed animals. These drawings could represent stories or the accumulation of knowledge, or they could have been part of rituals.

In any of these scenarios, Miyagawa suggests, cave art displays properties of language in that “you have action, objects, and modification.” This parallels some of the universal features of human language — verbs, nouns, and adjectives — and Miyagawa suggests that “acoustically based cave art must have had a hand in forming our cognitive symbolic mind.”

Future research: More decoding needed

To be sure, the ideas proposed by Miyagawa, Lesure, and Nobrega merely outline a working hypothesis, which is intended to spur additional thinking about language’s origins and point toward new research questions.

Regarding the cave art itself, that could mean further scrutiny of the syntax of the visual representations, as it were. “We’ve got to look at the content” more thoroughly, says Miyagawa. In his view, as a linguist who has looked at images of the famous Lascaux cave art from France, “you see a lot of language in it.” But it remains an open question how much a re-interpretation of cave art images would yield in linguistics terms.

The long-term timeline of cave art is also subject to re-evaluation on the basis of any future discoveries. If cave art is implicated in the development of human language, finding and properly dating the oldest known such drawings would help us place the orgins of language in human history — which may have happened fairly early on in our development.

“What we need is for someone to go and find in Africa cave art that is 120,000 years old,” Miyagawa quips.

At a minimum, a further consideration of cave art as part of our cognitive development may reduce our tendency to regard art in terms of our own experience, in which it probably plays a more strictly decorative role for more people.

“If this is on the right track, it’s quite possible that … cross-modality transfer helped develop a symbolic mind,” Miyagawa says. In that case, he adds, “art is not just something that is marginal to our culture, but central to the formation of our cognitive abilities.”

Author: Peter Dizikes | Source: Massachusetts Institute of Technology [February 21, 2018]

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Homo erectus may have sailed to islands and used language

They had bodies similar to modern humans, could make tools, and were possibly the first to cook. Now one expert is arguing that Homo erectus might have been a mariner – complete with sailing lingo.

Language was necessary for the spread of toolmaking technology, as well as for boat-building and sailing,
researchers suggest [Credit: Alamy Stock Photo]

Homo erectus first appeared in Africa more than 1.8m years ago and is thought to be the first archaic human to leave the continent.

H. erectus fossils have turned up not only in Southern Europe, but as far afield as China and Indonesia. Some argue that the mysterious hominid Homo floresiensis, discovered on the island of Flores, could be descended from H. erectus – although others disagree.

“Oceans were never a barrier to the travels of Erectus. He travelled all over the world, travelled to the island of Flores, across one of the greatest ocean currents in the world,” said Daniel Everett, professor of global studies at Bentley University, and author of How Language Began. “They sailed to the island of Crete and various other islands. It was intentional: they needed craft and they needed to take groups of twenty or so at least to get to those places.”

While Everett is not the first to raise the controversial possibility that H. erectus might have fashioned some sort of seagoing vessel, he believes that such capabilities mean that H. erectus must also have had another skill: language.

“Erectus needed language when they were sailing to the island of Flores. They couldn’t have simply caught a ride on a floating log because then they would have been washed out to sea when they hit the current,” said Everett, presenting his thesis at the meeting of the American Association for the Advancement of Science in Austin. “They needed to be able to paddle. And if they paddled they needed to be able to say ‘paddle there’ or ‘don’t paddle.’ You need communication with symbols not just grunts.”

It is unknown when language emerged among hominids; some argue that it is a feature only of our own species, Homo sapiens, which suggests a timing of no earlier than 200,000 years ago. But Everett believes it goes back further than that.

Everett says that H. erectus would have been unable to make the same range of sounds as we do, not least because they lacked the version of a gene necessary for speech and language to develop – known as FOXP2 – found in modern humans and Neanderthals, although it is not clear whether Neanderthals had language. But he argues that as few as two sounds are needed for a language, and that it is likely H.erectus could make more than that.

“They had what it took to invent language – and language is not as hard as many linguists have led us to believe. If you have symbols in a linear order then you have a grammar,” said Everett. “Homo erectus spoke and invented the Model T Ford of language. We speak the Tesla form, but their Model T form was not a proto-language it was a real language.”

“Everybody talks about Homo erectus as a stupid ape-like creature, which of course describes us just as well, and yet what I want to emphasise is that Erectus was the smartest creature that had ever walked the Earth,” he said.

The theory received mixed reactions from others. Kevin Laland, professor of behavioural and evolutionary biology at the University of St Andrews, said he agreed with Everett. “The important thing to recognise is that language did not appear in modern form all at once, but gradually evolved from a protoculture comprising just a handful of words with little grammatical structure. Certainly, it is highly plausible that Homo erectus had a protolinguistic capability,” he said, adding that work by his own team hinted it was possible. “Our experiment suggests that it would have been very difficult for knowledge of how to manufacture Homo erectus’s Acheulian stone tools to spread without a simple form of language. The study also demonstrates that stone toolmaking would had created a selection pressure favouring increased linguistic capabilities,” he said.

But others say that there is little evidence that H. erectus was a sophisticated seafarer, let alone had a language. “I don’t accept that, for example, [Homo] erectus must have had boats to get to Flores,” said Chris Stringer, head of human origins at the Natural History Museum in London. “Tsunamis could have moved early humans on rafts of vegetation.”

That said, Stringer notes that Homo heidelbergensis, another extinct relative of ours that lived between 700,000 and 300,000 years ago, might have been capable of some sort of chat. “I think [Homo] heidelbergensis had a complex enough life to require speech, though not at the level of modern human language. With [Homo] erectus, I’m not so sure,” said Stringer, adding that the ability of H. erectus to make and use tools is not, as some have argued, convincing evidence. “Chimps and crows make and use tools without a human kind of language,” he said.

Author: Nicola Davis | Source: The Guardian [February 20, 2018]

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Brain size of human ancestors evolved gradually over 3 million years

Modern humans have brains that are more than three times larger than our closest living relatives, chimpanzees and bonobos. Scientists don't agree on when and how this dramatic increase took place, but new analysis of 94 hominin fossils shows that average brain size increased gradually and consistently over the past three million years.

Models of human ancestors brain size compared to modern day humans
[Credit: Matt Wood, UChicago]

The research, published this week in the Proceedings of the Royal Society B, shows that the trend was caused primarily by evolution of larger brains within populations of individual species, but the introduction of new, larger-brained species and extinction of smaller-brained ones also played a part.

"Brain size is one of the most obvious traits that makes us human. It's related to cultural complexity, language, tool making and all these other things that make us unique," said Andrew Du, PhD, a postdoctoral scholar at the University of Chicago and first author of the study. "The earliest hominins had brain sizes like chimpanzees, and they have increased dramatically since then. So, it's important to understand how we got here."

Du began the work as a graduate student at the George Washington University (GW). His advisor, Bernard Wood, GW's University Professor of Human Origins and senior author of the study, gave his students an open-ended assignment to understand how brain size evolved through time. Du and his fellow students, who are also co-authors on the paper, continued working on this question during his time at George Washington, forming the basis of the new study.

"Think about the entrance to a building. You can reach the front door by walking up a ramp, or you can take the steps," Wood said. "The conventional wisdom was that our large brains had evolved because of a series of step-like increases each one making our ancestors smarter. Not surprisingly the reality is more complex, with no clear link between brain size and behavior."

Modern human brains (left) are more than three times larger than our closest relatives, chimpanzees (right)
[Credit: Andrew Du, UChicago]

"The moral is this: When you don't understand something ask a bunch of bright and motivated students to figure it out," he said.

Du and his colleagues compared published research data on the skull volumes of 94 fossil specimens from 13 different species, beginning with the earliest unambiguous human ancestors, Australopithecus, from 3.2 million years ago to pre-modern species, including Homo erectus, from 500,000 years ago when brain size began to overlap with that of modern-day humans.

The researchers saw that when the species were counted at the clade level, or groups descending from a common ancestor, the average brain size increased gradually over three million years. Looking more closely, the increase was driven by three different factors, primarily evolution of larger brain sizes within individual species populations, but also by the addition of new, larger-brained species and extinction of smaller-brained ones. The team also found that the rate of brain size evolution within hominin lineages was much slower than how it operates today, although why this discrepancy exists is still an open question.

The study quantifies for the first time when and by how much each of these factors contributes to the clade-level pattern. Du said he likens it to how a football coach might build a roster of bigger, strong players. One way would be to make all the players hit the weight room to bulk up. But the coach could also recruit new, larger players and cut the smallest ones.

"That's exactly what we see going on in brain size," he said. "The dominant process is like the players hitting the gym. They're evolving larger brains within a population. But we also see speciation events adding larger-brained daughter species, or recruiting bigger players, and we see extinction, or cutting the smallest players too."

Source: University of Chicago Medical Center [February 20, 2018]

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First 3-D morphometric study of the molars of Sima de los Huesos

The Dental Anthropology Group of the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) forms part of the team which has just published a paper in American Journal of Physical Anthropology on the morphological analysis of the dentin in the lower molars of the population of the archaeological site of Sima de los Huesos (Atapuerca, Burgos), using three-dimensional geometric morphometry, in order to study the origin of the Neanderthals.

Dentine surface illustrating the landmarks used to capture their shape
[Credit: Hanegraef et al.]

In this innovative study, in which scientists from University College London have also participated, 85 molars have been analyzed using computerized axial microtomography in the laboratories of the CENIEH, which has allowed high-resolution virtual sections to be obtained.

Geometric morphometric analyses performed hitherto have been based on using two-dimensional images such as photographs, although the application of new technologies such as micro-CT and the 3D reconstruction software Amira have made possible the first work of geometric morphometry using three-dimensional images.

“With the results obtained, we have been able to ratify once again the similarities found between the population of Sima de los Huesos and the Neanderthals, and the differences between these and Homo sapiens”, explains the director of the CENIEH María Martinón-Torres, co-author of this work.

Nevertheless, despite the notable affinities with Homo neanderthalensis, the population of Sima de los Huesos displays lower intra-population variability and has certain features even more derived than the Neanderthals themselves.

Neanderthal accretion

The principal objective of the authors, in addition to reviewing the current hypotheses which explain the origin of the Neanderthals, has been to verify the reliability of the Neanderthal accretion model, which suggests that Neanderthal characteristics did not develop in a linear and continuous manner, but  rather accreted abruptly at different periods.

“The results of this investigation favor the theory of a more complex evolutionary scenario for the European continent during the Middle Pleistocene, with the coexistence of different populations and without rejecting possible hybridization between them”, concludes Martinón-Torres.

Source: CENIEH [February 19, 2018]

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Ancient genome study identifies traces of indigenous “Taíno” in present-day Caribbean populations

A thousand-year-old tooth has provided genetic evidence that the so-called "Taíno," the first indigenous Americans to feel the full impact of European colonisation after Columbus arrived in the New World, still have living descendants in the Caribbean today.

First encounter. Columbus landing in the New World [Credit: Library of Congress]

Researchers were able to use the tooth of a woman found in a cave on the island of Eleuthera in the Bahamas to sequence the first complete ancient human genome from the Caribbean. The woman lived at some point between the 8th and 10th centuries, at least 500 years before Columbus made landfall in the Bahamas.

The results provide unprecedented insights into the genetic makeup of the Taíno -- a label commonly used to describe the indigenous people of that region. This includes the first clear evidence that there has been some degree of continuity between the indigenous peoples of the Caribbean and contemporary communities living in the region today.

Such a link had previously been suggested by other studies based on modern DNA. None of these, however, was able to draw on an ancient genome. The new research finally provides concrete proof that indigenous ancestry in the region has survived to the present day.

Comparing the ancient Bahamian genome to those of contemporary Puerto Ricans, the researchers found that they were more closely related to the ancient Taíno than any other indigenous group in the Americas. However, they argue that this characteristic is unlikely to be exclusive to Puerto Ricans alone and are convinced that future studies will reveal similar genetic legacies in other Caribbean communities.

The findings are likely to be especially significant for people in the Caribbean and elsewhere who have long claimed indigenous Taíno heritage, despite some historical narratives that inaccurately brand them "extinct." Such misrepresentations have been heavily criticised by historians and archaeologists, as well as by descendant communities themselves, but until now they lacked clear genetic evidence to support their case.

The study was carried out by an international team of researchers led by Dr Hannes Schroeder and Professor Eske Willerslev within the framework of the ERC Synergy project NEXUS1492. The findings are published in the journal Proceedings of the National Academy of Sciences.

Lead author Schroeder, from the University of Copenhagen who carried out the research as part of the NEXUS1492 project, said: "It's a fascinating finding. Many history books will tell you that the indigenous population of the Caribbean was all but wiped out, but people who self-identify as Taíno have always argued for continuity. Now we know they were right all along: there has been some form of genetic continuity in the Caribbean."

Willerslev, who has dual posts at St John's College, University of Cambridge, and the University of Copenhagen, said: "It has always been clear that people in the Caribbean have Native American ancestry, but because the region has such a complex history of migration, it was difficult to prove whether this was specifically indigenous to the Caribbean, until now."

The researchers were also able to trace the genetic origins of the indigenous Caribbean islanders, showing that they were most closely related to Arawakan-speaking groups who live in parts of northern South America today. This suggests that the origins of at least some the people who migrated to the Caribbean can be traced back to the Amazon and Orinoco Basins, where the Arawakan languages developed.

The Caribbean was one of the last parts of the Americas to be populated by humans starting around 8,000 years ago. By the time of European colonization, the islands were a complex patchwork of different societies and cultures. The "Taíno" culture was dominant in the Greater, and parts of the Lesser Antilles, as well as the Bahamas, where the people were known as Lucayans.

To trace the genetic origins of the Lucayans the researchers compared the ancient Bahamian genome with previously published genome-wide datasets for over 40 present-day indigenous groups from the Americas. In addition, they looked for traces of indigenous Caribbean ancestry in present-day populations by comparing the ancient genome with those of 104 contemporary Puerto Ricans included in the 1000 Genomes Project. The 10-15% of Native American ancestry in this group was shown to be closely related to the ancient Bahamian genome.

Jorge Estevez, a Taíno descendant who works at the National Museum of the American Indian in New York and assisted the project team, said that as a boy growing up in the United States, he was told stories about his Taíno ancestors at home, but at school was taught that the same ancestors had died out. "I wish my grandmother were alive today so that I could confirm to her what she already knew," he added. "It shows that the true story is one of assimilation, certainly, but not total extinction. I am genuinely grateful to the researchers. Although this may have been a matter of scientific inquiry for them, to us, the descendants, it is truly liberating and uplifting."

Although indigenous Caribbean communities were island-based, the researchers found very little genomic evidence of isolation or inbreeding in the ancient genome. This reinforces earlier genetic research led by Willerslev, which suggests that early human communities developed surprisingly extensive social networks, long before the term had digital connotations. It also echoes ongoing work by researchers at the Faculty of Archaeology in Leiden and others indicating the connectedness of indigenous Caribbean communities.

Professor Corinne Hofman from Leiden University and PI of the NEXUS1492 project, said: "Archaeological evidence has always suggested that large numbers of people who settled the Caribbean originated in South America, and that they maintained social networks that extended far beyond the local scale. Historically, it has been difficult to back this up with ancient DNA because of poor preservation, but this study demonstrates that it is possible to obtain ancient genomes from the Caribbean and that opens up fascinating new possibilities for research."

Source: University of Cambridge [February 19, 2018]

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Did humans domesticate themselves?

Human 'self-domestication' is a hypothesis that states that among the driving forces of human evolution, humans selected their companions depending on who had a more pro-social behavior. Researchers from a team of the UB led by Cedric Boeckx, ICREA professor at the Department of Catalan Philology and General Linguistics and member of the Institute of Complex Systems of the University of Barcelona (UBICS), found out new genetic evidence for this evolutionary process.

Craniofacial differences between modern humans and Neanderthals (top)
and between dogs and wolves (bottom) [Credit: PLOS ONE]

The study, published in the science journal PLOS ONE, compared the genomes of modern humans to those of several domesticated species and their wild animal type, in order to look for overlapping genes that were associated with domestication traits, such as docility or a gracile physiognomy. The results showed a statistically significant number of genes associated with domestication which overlapped between domestic animals and modern humans, but not with their wild equals, like Neanderthals.

According to the researchers, these results reinforce the human self-domestication hypothesis and "help to shed light on one aspect that makes us human, our social instinct."

A new type of evidence: the genomes of extinct human relatives

Self-domestication would occur in species that display anatomical and behavioural features which are typical of domestic animals in comparison to their wild types. However, in these cases, domestication would have taken place without any other species domesticating the others. Several studies proposed the hypothesis stating that humans -and other species such as bonobos- domesticated themselves. The aim of this study was to find out biological evidence of the self-domestication by looking at a new type of data that has become available: the genomes of our extinct relatives, such as Neanderthals or Denisovans.

"One reason that made scientists claim that humans are self-domesticated lied within our behavior: modern humans are docile and tolerant, like domesticated species, our cooperative abilities and pro-social behaviour are key features of our modern cognition," says Cedric Boeckx. "The second reason is that modern humans, when compared to Neanderthals, present a more gracile phenotype that resembles the one seen in domesticates when compared to their wild-type cousins," added the expert.

To identify signs of a self-domestication process in humans, researchers made a list of genes associated with domestication features in humans, out of the comparison with the genome in Neanderthals and Denisovans, extinct human species. Then, they compared this list to the genome from some domesticated animals and their wild relatives, for instance, dogs compared to wolves, and cattle compared to wisents.

Results showed that this overlap was only relevant between domesticated species and humans. "Those modern humans' selected genes under selection may prove central to a relevant process of domestication, given that these interactions may provide significant data on relevant phenotypic traits," said Boeckx.

Intersection between modern humans and domesticated species

Researchers also employed other statistical measures, including control species, to certify these results. Their aim was to rule out the fact that these genes could be randomly overlapped between humans and domesticated animals when compared, so they compared the genomes among other great apes. "We found that chimpanzees, orangutans and gorillas do not show a significant overlap of genes under positive selection with domesticates. Therefore, it seems there is a 'special' intersection between humans and domesticated species, and we take this to be evidence for self-domestication," Boeckx said.

Researchers note that there is still more experimental work to do in order to find out the anatomical, cognitive and behavioural characteristics that are associated with these genes. "We suspect it will cover the anatomical, cognitive, and behavioral characteristics that researchers used to motivate the idea of self-domestication. We think that the overlap we found could help us explain our special mode of cognition and why we are strikingly cooperative, but this remains to be put to the test. In a sense, what we did is narrow down the set of genes to examine experimentally," concluded Cedric Boeckx.

Source: Universidad de Barcelona [February 15, 2018]

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Interdisciplinary approach yields new insights into human evolution

The evolution of human biology should be considered part and parcel with the evolution of humanity itself, proposes Nicole Creanza, assistant professor of biological sciences. She is the guest editor of a new themed issue of the Philosophical Transactions of the Royal Society B, the oldest scientific journal in the world, that focuses on an interdisciplinary approach to human evolution.

Credit: iStock

Stanford professor Marc Feldman and Stanford postdoc Oren Kolodny collaborated with Creanza on the special issue.

"Within the blink of an eye on a geological timescale, humans advanced from using basic stone tools to examining the rocks on Mars; however, our exact evolutionary path and the relative importance of genetic and cultural evolution remain a mystery," said Creanza, who specializes in the application of computational and theoretical approaches to human and cultural evolution, particularly language development. "Our cultural capacities-to create new ideas, to communicate and learn from one another, and to form vast social networks-together make us uniquely human, but the origins, the mechanisms, and the evolutionary impact of these capacities remain unknown."

The special issue brings together researchers in biology, anthropology, archaeology, economics, psychology, computer science and more to explore the cultural forces affecting human evolution from a wider perspective than is usually taken.

"Researchers have begun to recognize that understanding non-genetic inheritance, including culture, ecology, the microbiome, and regulation of gene expression, is fundamental to fully comprehending evolution," said Creanza. "It is essential to understand the dynamics of cultural inheritance at different temporal and spatial scales, to uncover the underlying mechanisms that drive these dynamics, and to shed light on their implications for our current theory of evolution as well as for our interpretation and predictions regarding human behavior."

In addition to an essay discussing the need for an interdisciplinary approach to human evolution, Creanza included an interdisciplinary study of her own, examining the origins of English's contribution to Sranan, a creole that emerged in Suriname following an influx of indentured servants from England in the 17th century.

Creanza, along with linguists Andre Sherriah and Hubert Devonish of the University of the West Indes and psychologist Ewart Thomas from Stanford, sought to determine the geographic origins of the English speakers whose regional dialects formed the backbone of Sranan. Their work combined linguistic, historical and genetic approaches to determine that the English speakers who influenced Sranan the most originated largely from two counties on opposite sides of southern England: Bristol, in the west, and Essex, in the east.

"Thus, analyzing the features of modern-day languages might give us new information about events in human history that left few other traces," Creanza said.

Author: Liz Entman | Source: Vanderbilt University [February 13, 2018]

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