Swarms of humans likely overwhelmed Neanderthals

Cambridge researchers give evidence of modern humans migrating out of Africa with 10 times the population of Neanderthals in central and western Europe.

New research sheds light on why – after 300,000 years of domination – European Neanderthals abruptly disappeared. Researchers from the University of Cambridge say it’s likely that modern humans from Africa swarmed over the region, arriving with more than 10 times the population of the Neanderthal inhabitants. The study appears in the July 29, 2011 issue of Science.

Map showing the migration routes of modern humans out of Africa. Image Credit: Dora Kemp, McDonald Institute for Archaeological Research

The reason for the disappearance of the European Neanderthal populations across the continent around 40,000 years ago has long remained one of the great mysteries of human evolution. After 300 millennia of apparently flourishing in the cold environments of central and western Europe, they were rapidly replaced over all areas of the continent by anatomically and genetically “modern” Homo sapiens, who evolved in the tropical environments of Africa.

The Cambridge researchers did a statistical analysis of archaeological evidence from the largest concentration of Neanderthal and early modern human sites in Europe – the Perigord region of southwestern France. They found a sharp increase in the number of sites occupied by modern humans – many more stone tools and animal food remains, and bigger areas of occupation in the sites. These findings reveal much larger and apparently more socially integrated groupings.

Model of a Neanderthal male at the Zagros Paleolithic Museum, Kermanshah, Iran. Via Wikimedia

Faced with this dramatic increase of modern humans, the capacity of the Neanderthal groups to compete for living sites, animal food supplies (principally reindeer, horse, bison and red deer), and scarce fuel supplies for surviving the harsh winters would have been massively undermined. According to the researchers, there would have been inevitable, repeated conflicts between the two populations for occupation of the most attractive locations and richest food supplies.

The evidence suggests that incoming groups possessed superior hunting technologies and equipment, such as more effective and longer-range hunting spears, and probably more efficient procedures for processing and storing food supplies over the prolonged glacial winters. They also appear to have had more wide-ranging social contacts with adjacent human groups, which would allow for trade and exchange of essential food supplies in times of food scarcity.

Paul Mellars, Department of Archaeology, said:

Faced with this kind of competition, the Neanderthals seem to have retreated initially into more marginal and less attractive regions of the continent and eventually – within a space of at most a few thousand years – for their populations to have declined to extinction, perhaps accelerated further by sudden climatic deterioration across the continent around 40,000 years ago.

Model of a Neanderthal child. Via Wikipedia

Whether the incoming groups also possessed more highly developed brains than the Neanderthals remains a matter of debate. But the sudden appearance of a wide range of sophisticated art forms (including cave paintings), the large-scale production of decorative items (such as perforated stone and ivory beads, and imported sea shells), and clearly symbolic markings on bone and ivory tools – all entirely lacking among the Neanderthals – strongly points to more elaborate systems of social communication among the modern groups.

All of these more complex behavioral patterns seem to have developed first among the ancestral African Homo sapiens populations at least 20,000 to 30,000 years before their dispersal from Africa and progressive colonization (and replacement of earlier populations) across all regions of Europe and Asia from around 60,000 years onwards.

If, as the latest genetic evidence strongly suggests, the African Homo sapiens and European Neanderthal populations had been evolving separately for at least half a million years, then the emergence of significant contrasts in mental capacities would not be a surprising development, in evolutionary terms.

Bottom line: Cambridge researchers, including Paul Mellars, have published a paper in the July 29, 2011 issue of Science, showing a statistical analysis of archaeological data from Neanderthal and modern human sites in the Perigord region of France. Their research shows that Neanderthal populations were likely overwhelmed by an influx of Homo sapiens from Africa.

Read more at University of Cambridge

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New timeline for first early human exodus out of Africa

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