DNA taken from a 36,000 year old fossil skeleton found in Russia shows the early divergence of Eurasians after they left Africa as well as the ancient roots of Europeans.
The findings also reveal when Neanderthals and modern humans from Africa interbred, which was about 54,000 years ago, the Faculty of Science - University of Copenhagen reported.
The DNA was taken from one of the earliest-known Europeans who died more than 36,000 years ago at the site of Kostenki 14 in western Russia. The genome showed people had dispersed beyond Africa and Eurasia before the individual's time. These ancient people separated into three populations and developed characteristic that set them apart from their African ancestors.
These populations continued to develop in this way until the arrival of farmers in the Middle East in the past 8,000 years.
"What we can see from Kostenki and other ancient genomes is that for 30,000 years there was a single meta-population in Europe. These Palaeolithic hunter-gatherer groups split up, mixed, dispersed and changed, and through ancient genomes we can trace the genetic thread of their shared ancestry," said Lundbeck Foundation Professor Eske Willerslev, leader of the research team.
The genome analysis showed people from the Kostenki contributed to the genes seen in the boy from Mal'ta, who perished in Siberia 26,000 years ago and whose descendants were found across Europe and the Americas.
"It is not just a question of who they were, but what it tells us about how they lived. 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 Mirazón Lahr and Robert Foley from the University of Cambridge's Leverhulme Centre for Human Evolutionary Studies.
The genome of the man from Kostenki, whose genomes included Neanderthal genes, showed early there was an "isolated admixture" with Neanderthals in the early colonization of Eurasia.
"Kostenki 14 actually has a slightly higher percentage of Neanderthal genes than ever observed before, and the genetic fragments that the man from Kostenki inherited from a Neanderthal ancestor are larger, not yet broken by the thousands of natural recombination events that have occurred since. This allowed us to estimate the time of human-Neanderthal admixture to 54,000 years ago," said Professor Rasmus Nielsen from the University of California at Berkeley.
A segment of the Kostenki genome was passed to populations from the Middle East, who later introduced farming and lighter skin to European populations.
"Ancient genomes add a time and space stamp to our genetic history. Recovering the whole genome, rather than just small fragments as happened in the past, adds the power of genomics. This 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 Professor Eske. Willerslev
