New DNA evidence suggests a major upheaval of humans living around Europe at the end of the last Ice Age, apparently linked to severe climatic instability.
Ancient bones and teeth of people who lived in Europe over the span of 30,000 years were used to establish this unknown period of human history, in research published today in Current Biology.
Johannes Krause, of the Max Planck Institute, said little was known about the population of the first modern humans in Europe because there had been a lack of genetic data from that time period.
“We uncovered a completely unknown chapter of human history: a major population turnover in Europe at the end of the last Ice Age”
Mitochondrial genomes of 35 hunter-gatherers, inferred from DNA in teeth and bones, who lived in Italy, Germany, Belgium, France, the Czech Republic, and Romania between 35,000 and 7,000 years ago. Mitochondria, commonly called the “powerhouses” of cells, are often used to determine maternal ancestry as their DNA is passed from mother to child.
Three of those individuals lived in present-day Belgium and France before the Last Glacial Maximum – the coldest period in the last Ice Age. Their mitochondrial DNA showed they belonged to haplogroup M – a remarkable finding because haplogroup M is effectively absent in modern Europeans but is common throughout Asian, Australasian and Native American populations.
That distribution had led scientists to conclude that non-African humans dispersed multiple times across Eurasia and Australasia. But the researchers say the discovery of the M haplotype in Europe suggested that all non-Africans dispersed rapidly from a single population about 50,000 years ago. Later the M haplotype was apparently lost from Europe.
“When the Last Glacial Maximum began around 25,000 years ago, hunter-gatherer populations retreated south to a number of putative refugia, and the consequent genetic bottleneck probably resulted in the loss of this haplogroup,” said University of Tübingen’s Cosimo Posth.
But the biggest surprise to the researchers was evidence of a major population turnover in Europe around 14,500 years ago, right as the climate began to warm at the end of the last Ice Age. Models suggested that during the period of climatic upheaval, the descendants of the hunter-gatherers who survived through the Last Glacial Maximum were largely replaced by a population from another area.
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Featured image: Hohle Fels, Swabian Jura, Germany. © Alb-Donau-Kreis Tourismus.