A ground-breaking new study on DNA recovered from a fossil of one of the earliest known Europeans — a man who lived 36,000 years ago in Kostenki, western Russia — has shown that the earliest European humans’ genetic ancestry survived the Last Glacial Maximum: the peak point of the last ice age.
The study also uncovers a more accurate timescale for when humans and Neanderthals interbred, and finds evidence for an early contact between the European hunter-gatherers and those in the Middle East — who would later develop agriculture and disperse into Europe about 8,000 years ago, transforming the European gene pool.
Scientists now believe Eurasians separated into at least three populations earlier than 36,000 years ago: Western Eurasians, East Asians and a mystery third lineage, all of whose descendants would develop the unique features of most non-African peoples — but not before some interbreeding with Neanderthals took place.
Led by the Centre for GeoGenetics at the University of Copenhagen, the study was conducted by an international team of researchers from institutions including the University of Cambridge’s Departments of Archaeology and Anthropology, and Zoology, and is published today in the journal Science.
The new study allows scientists to closer estimate this ‘event’ as occurring around 54,000 years ago, before the Eurasian population began to separate. This means that, even today, anyone with a Eurasian ancestry — from Chinese to Scandinavian and North American — has a small element of Neanderthal DNA.
However, despite Western Eurasians going on to share the European landmass with Neanderthals for another 10,000 years, no further periods of interbreeding occurred.
Unique to the Kostenki genome is a small element it shares with people who live in parts of the Middle East now, and who were also the population of farmers that arrived in Europe about 8,000 years ago and assimilated with indigenous hunter-gatherers. This early contact is surprising, and provides the first clues to a hereto unknown lineage that could be as old as — or older than — the other major Eurasian genetic lines. These two populations must have interacted briefly before 36,000 years ago, and then remained isolated from each other for tens of millennia.
Mirazón Lahr points out that, while Western Eurasia was busy mixing as a ‘meta-population’, there was no interbreeding with these mystery populations for some 30,000 years — meaning there must have been some kind of geographic barrier for millennia, despite the fact that Europe and the Middle East seem, for us at least, to be so close geographically. But the Kostenki genome not only shows the existence of these unmapped populations, but that there was at least one window of time when whatever barrier existed became briefly permeable.
— source sciencedaily.com