Humans were in the Arctic 45,000 years ago

Evidence for a human presence inside the Arctic Circle 15,000 years earlier than previously believed

In 2012, archaeologists recovered the remains of a woolly mammoth from frozen sediment on a coastal bluff on the eastern shore of Yenisei Bay, 1.8 km (1.1 miles) north of the Sopochnaya Karga weather station, at 71°54′19.2″N 82°4′23.5″E. The mammoth had clearly been killed by humans, and radiocarbon dating has established that the remains are 45,000 years old.

Previously, the earliest evidence for a human presence inside the Arctic Circle is the Yana Rhinoceros Horn site on the Lower Yana River at 71°N. Artefacts recovered at this site include spear shafts made from rhinoceros and mammoth horn, and a variety of stone tools. The site dates to around 30,000 years ago.

However, the Sopochnaya Karga evidence suggests that humans had mastered the challenging conditions of the Arctic well before this date. Damage and injuries to the mammoth’s ribs, shoulder blades, tusks and lower jawbone were consistent with it having been attacked and killed with thrusting spears and light projectile weapons, and subsequently butchered.

The hunters are assumed to be modern humans, though in the absence of fossil evidence this cannot be confirmed. There is fossil and ancient DNA evidence confirming that modern humans were at Ust’-Ishim in western Siberia 45,000 years ago, but this site lies well to the south at 57°N.

Reference:

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Pitulko, V. et al., Early human presence in the Arctic: Evidence from 45,000-year-old mammoth remains. Science 351 (6270), 260-263 (2016).x

‘Iceman’ stomach bug points to more complex picture of early European settlement

Researchers obtain genome of Helicobacter pylori from 5,000-year-old stomach contents

The stomach bacterium Helicobacter pylori is found in roughly half of the world’s present-day population, although it causes symptoms in only around 10 to 15 percent of cases. The bacterium’s association with humans is very ancient, possibly originating in East Africa 58,000 years ago. Since then, various strains have emerged as humans dispersed around the world. Thus differing strains reflect differing geographical origins and are informative about past human migrations.

The European strain hpEurope is believed to have resulted from hybridization between two ancestral strains known as AE1 and AE2. It is thought that AE1 emerged in Central Asia and later evolved into the present-day strain hpAsia2. AE2 is thought to have arisen in Northeast Africa. The two strains have been thought to have hybridized in Southwest Asia 50,000 years ago, with the recombined strain arriving in Europe when populations expanded after the Last Glacial Maximum.

To test this model, researchers obtained a genome of the bacterium from the stomach contents of ‘Ötzi’, the frozen 5,000 year old corpse that was found in 1991 in the Ötztal Alps on the border between Austria and Italy. Despite the age of Ötzi’s remains, it was thought that any H. pylori present would be similar to the present-day hpEurope strain.

Instead, it turned out that Ötzi was carrying a strain that most closely resembled hpAsia2, which is rare in modern Europeans. This suggests that the hybridisation with the African H. pylori strain actually occurred more recently than 5,000 years ago, in turn implying that there was a Chalcolithic migration from Africa. The study presents interesting evidence that the history of human settlement of Europe during this period is more complex than previously believed.

Reference:

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Maixner, F., Krause-Kyora, B., Turaev, D., Herbig, A. & Hoopmann, M., The 5300-year-old Helicobacter pylori genome of the Iceman. Science 351 (6269), 162-165 (2016).

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Modern humans were in China 100,000 years ago

Assignment of fossil teeth from Fuyan Cave to Homo sapiens is ‘unequivocal’

Ever since genetic evidence emerged to support the ‘recent Out of Africa’ model of modern human origins, the orthodox view is that until around 60,000 years ago modern humans were confined to Africa and a short range extension into Southwest Asia. The latter is thought to have been brought to an end as colder, more arid climatic conditions set in around 90,000 years ago. The model has been challenged by archaeological evidence suggesting that modern humans were established on the Arabian Peninsula 125,000 years ago and had reached India 77,000 years ago.

What has up until now been lacking is unequivocal fossil evidence significantly earlier than around 45,000 years old. Controversial evidence had previously been reported from two sites in southern China. An age of up to 139,000 years old has been claimed for the Liujiang Skull, discovered in 1958, but the exact geological position of the find was not documented and the skull could actually be as little as 30,000 years old. A lower jawbone and two molar teeth from Zhirendong (‘Homo sapiens cave’) in Guizhou Province have been securely dated to 106,000 years old, but it is not certain that these remains belonged to a modern human.

However, the discovery has now been reported of 47 teeth at the newly-excavated site of Fuyan Cave in Daoxian, Hunan Province. Uranium series dating of associated stalagmite fragments gave a minimum age of 80,000 years old for the teeth and faunal dating gave a maximum age of 120,000 years old. The teeth were compared with those of Late Pleistocene humans from Europe, Asia and Africa and were found to fall consistently within the Homo sapiens size range. They are generally smaller than other Late Pleistocene samples from Asia and Africa, and are closer to European Late Pleistocene samples and the teeth of present-day people. They resemble the latter far more closely than they do the teeth of Neanderthals or Homo erectus.

The announcement adds a radical new dimension to the history of modern human dispersals in Eurasia.

Reference:

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Liu, W. et al., The earliest unequivocally modern humans in southern China. Nature 526, 696-699 (2015).x

Is the steppe migration theory of Indo-European origins correct after all?

Genetic study challenges Anatolian farmer hypothesis

One of the longest-running debates in the study of prehistory is the origin of the Indo-European language family. This group includes languages spoken from Great Britain and Ireland to India the steppes of Central Asia, and a connection between them was established as far back as the late eighteenth century. It is assumed that all originated from a single mother tongue, Proto-Indo-European (PIE), but where was PIE spoken?

Until the 1980s, the favoured Indo-European homeland was the Pontic-Caspian steppes north of the Black Sea and Caspian Sea. In a series of papers published from the 1950s through to the 1970s, Lithuanian-born Marija Gimbutas identified the Proto-Indo-Europeans with the Kurgan culture, named for a Russian word for the burial mounds with which the culture is associated. The Kurgan people originated in the lower Volga basin and the lower Dnieper region around 4500 BC. They lived as nomadic pastors, with an economy based on sheep, goats, cattle and pigs. Gimbutas saw them as highly-mobile, warlike people who used ox-drawn wagons and horses for transport. Between 4400 and 2800 BC, the Kurgan people mounted a series of hostile incursions from the steppes into Europe, Anatolia, the Caucasus, India and Central Asia. The peaceful, settled Neolithic farmers living in the regions were no match for the invaders, whose language (PIE) and culture came to predominate.

Although some disputed the warlike nature of the Kurgan people, the steppe hypothesis was widely accepted. However, in 1987, British archaeologist Colin Renfrew put forward a rival view in which he claimed that PIE was spoken and dispersed by Neolithic farmers originating from Anatolia before 6500 BC. The spread of agriculture distributed their language over a vast area. From Anatolia, the expansion had moved into Greece and onwards across Europe in wave of advance, expanding generation by generation as populations grew. Renfrew offered a choice of two scenarios as to the spread of the Indo-Iranian sub-family of languages: the first proposed a simple wave of advance similar to that proposed for Europe. The second invoked a modification of the steppe-invader model. Once the European wave of advance reached the steppe, nomadic pastoralism developed and the pastors moved swiftly east across the steppes and into Iran and northern India. Renfrew later came down in favour of this second scenario.

The Renfrew model is supported by archaeological and genetic evidence for an agricultural expansion into Europe, with Neolithic farmers both replacing and intermarrying with existing Mesolithic hunter-gatherers. Further support has come from a 2012 study in which Bayesian statistics were applied to Indo-European languages. The results suggested that PIE originated in Anatolia and began to break up into its daughter tongues between 7500 and 6000 BC.

Despite the success of the Anatolian hypothesis, it is not without its faults. A common criticism is that PIE contains reconstructed words for the wheel and wheeled vehicles, which were not invented until long after the agricultural expansion into Europe.

The main weakness of the steppe model has been a lack of evidence for a major migration from the Eurasian steppe at that time. However, a study of ancient DNA obtained from just under a hundred Europeans living between 6000 and 1000 BC may address this issue. The results confirm that farmers reached Europe from Southwest Asia between 6000 and 5000 BC, but they also indicate a second, later migration. A close match was found between Yamnaya culture steppe pastors from Russia and Ukraine, dating to 3000 BC, and individuals of the Corded Ware culture of Northern Europe, dating to 2500 BC. The similarities indicate a large-scale migration into Europe from the east. While the language these migrants spoke is unknown, it probably originated in the Yamnaya homeland.

Consistent with these results is a new linguistic study suggesting that PIE originated around 4000 BC rather than between 7500 and 6000 BC. However, the methodology used has been criticised by the authors of the 2012 study.

It is also possible that the Yamnaya data represents a secondary migration of people descended from the original PIE-speaking Anatolian farmers, in which case the Yamnaya people might have spoken a derived Indo-European language ancestral to the present-day Balto-Slavic group rather than PIE itself.

Overall, the genetic results suggest that the true picture might be a synthesis of both Anatolian and steppe-migration models.

References:
(W. Haak et al. http://doi.org/z9d; 2015)

Cave art from Sulawesi was contemporary with Upper Palaeolithic European cave-painting tradition

U-series re-dating suggests that Indonesian cave art is almost 40,000 years old

The arrival of modern humans in Europe is marked by the appearance in the archaeological record of a sophisticated artistic tradition, which includes portable art objects and cave art. Archaeologists have long been puzzled by an apparent lack of antecedents for this artwork, either in Africa or on early modern human migration routes. It is difficult to see how a seemingly mature artistic tradition could arise de novo in Upper Palaeolithic Europe – but if the 40,000 year old cave paintings at sites such as Altamira and El Castillo really were the earliest cave art anywhere in the world, this must have been the case.

In the 1950s, rock art was reported from limestone caves in the Maros and Pangkep regions of the island of Sulawesi, Indonesia. Over 90 rock art sites are known, which have been extensively studied by Indonesian scholars and appear to belong two distinct periods. The art of the earlier period comprises hand stencils produced by spraying pigment over hands pressed against rock surface, together with a smaller number of large, naturalistic paintings of large Sulawesi mammals, including the anoa (a small bovid), the Celebes warty pig and the babirusa (a member of the pig family). The artwork of the later period is typified by small anthropomorphic depictions and a wide range of geometric signs, typically drawn using a black pigment. This later period has been associated with Austronesian migrants on stylistic grounds, and is thought to be no more than a few thousand years old.

The art of earlier period, though much older than that of the later period, was still thought to be less than 10,000 years old. However, recently-reported uranium series dates obtained for 14 paintings (12 hand stencils and two animal paintings) located at seven different sites indicate that it is much older. The oldest hand stencil was at least 39,900 years old and the oldest animal painting was at least 35,700 years old. The most recent hand stencil was no older than 27,200 years old, suggesting a tradition that endured for at least 13,000 years – comparable to the duration of the European cave painting tradition.

That contemporary traditions of cave art occurred in two regions as far apart as Europe and Indonesia implies either independent development or a common origin dating much further back in time. If the latter was the case, we can hope that even earlier depictions of human hands, figurative art and other images await discovery.

Reference:

1. Aubert, M. et al., Pleistocene cave art from Sulawesi, Indonesia. Nature 514, 223-227 (2014).

Prehistory of New World Arctic investigated in major new genetic study

Paleo-Eskimos were independent of Inuit and Native American expansions

In the 1980s, the American linguist Joseph Greenberg proposed that Native American languages could be classified within three families: Eskimo-Aleut, Na Dene and Amerind. He further suggested that each family corresponded to a separate migration into the New World from Siberia and concluded, therefore, that the New World had been peopled by three migrations. Greenberg’s views remained controversial for many years as most mitochondrial and Y-chromosomal genetic studies indicated that there had been no more than two migrations. In 2012, however, he was apparently vindicated when David Reich and his colleagues presented a high resolution study of 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. The results indicated that there had indeed been three migrations broadly corresponding to the three language families: specifically (i) First Americans, (ii) Eskimo-Aleuts and, (iii) Saqqaq and Na Dene speakers.

These results are built on by a major new study conducted by an international team numbering over fifty researchers led by geneticist Maanasa Raghavan from the University of Copenhagen. The study focussed on mitochondrial and genome-wide sequences obtained from ancient bone, hair and teeth samples of Arctic Siberia, Alaska, Canada, and Greenland, and high-coverage genomes of two present-day Greenlandic Inuit, two Siberian Nivkhs, one Aleutian Islander, and two Athabascan Native Americans.

From this data, researchers hoped to resolve issues regarding the complex archaeological record of the Early Paleo-Eskimos (Pre-Dorset/Saqqaq), the Late Paleo-Eskimos (Early Dorset, Middle Dorset, and Late Dorset), and the Thule cultures. They were able to show that the Paleo-Eskimos reached the New World in a single migration from Siberia around 3000 BC and displayed genetic continuity for more 4,000 years. About 700 years ago they were replaced by the Thule people, who were the ancestors of the present day Inuit.

While supporting Reich et al overall, the results indicated that the Saqqaq tradition and Na Dene speakers were not part of the same migratory wave: accordingly the Paleo-Eskimos must have arrived in a separate migration to the three waves identified by Reich et al, implying that the New World was populated by four migrations in all.

References:

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1.  Reich, D. et al., Reconstructing Native American population history. Nature 488, 370–374 (2012).

2.  Greenberg, J., Turner, C. & Zegura, S., The Settlement of the Americas: A Comparison of the Linguistic, Dental, and Genetic Evidence. Current Anthropology 27 (5), 477-497 (1986).

3.  Raghavan, M. et al., The genetic prehistory of the New World Arctic. Science 345 (620), 1020,1255832 (2014).

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