Ancient European Ancestors Interbred with Neanderthals and Survived the Ice Age

It turns out that humans managed to survive the peak point of the last ice age. Scientists have recovered DNA from a fossil of one of the earliest known Europeans, a man who lived 36,000 years ago in western Russia, and have found that our genetic ancestry stretches back further than expected.

In order to learn a bit more about our ancient ancestors-and the modern human, in turn-the scientists cross-referenced the ancient mans' complete genome, which is the second oldest modern human genome ever sequenced. They found a surprising genetic "unity" running from the first modern humans in Europe, which suggested that a "meta-population" of Palaeolithic hunter-gatherers with deep shared ancestry managed to survive through the Last Glacial Maximum and then colonize Europe.

In fact, it appears that European populations as a whole maintained the same genetic thread from their earliest establishment out of Africa until Middle Eastern populations arrived in the last 8,000 years, bringing agriculture and lighter skin color.

"That there was continuity from the earliest Upper Palaeolithic to the Mesolithic across a major glaciation is a great insight into the evolutionary processes underlying human success," said Marta Mirazon Lahr, co-author of the new study, in a news release. "For 30,000 years ice sheets came and went, at one point covering two-thirds of Europe. Old cultures died and new ones emerged-such as the Aurignacian and the Grevettian-over thousands of years, and the hunter-gatherer populations ebbed and flowed. But we now know that no new sets of genes are coming in: these changes in survival and cultural kit are overlaid on the same biological background."

This isn't all that the ancient DNA shows, though. The researchers also found a more accurate timescale for when humans and Neanderthals interbed. It appears that the even occurred about 54,000 years ago, before the Eurasian population began to separate. This means that anyone with a Eurasian ancestry has a small bit of Neanderthal DNA.

"This work reveals the complex web of population relationships in the past, generating for the first time a firm framework with which to explore how humans responded to climate change, encounters with other populations, and the dynamic landscapes of the ice age," said Eske Willerslev, lead author of the new study.

The findings are published in the journal Science.