Scientists have uncovered what they believe is the oldest human DNA sample ever found, a discovery that could help unravel the mystery of how humans spread out over the planet. Phys.org reports that DNA came from a Homo Sapiens femur bone that was found accidentally on the bank of a west Siberian River in 2008; it is believed to have belonged to a man who died about 45,000 years ago. The DNA found in that bone holds traces of Neanderthals, a cousin of early humans who lived nearby in Eurasia before suddenly disappearing.
The new study published in the journal Nature and headed by Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology, supports the theory known as the “Out of Africa” scenario that says early humans evolved in East Africa around 200,000 years ago and then left the continent. The ability to date when humans bred with their Neanderthal counterparts in Eurasia would indicate an important part of Homo Sapiens journey out of Africa.
Research shows the Siberian bone contains more Neanderthal DNA than non-Africans today, but it comes in relatively long strips – unlike the Neanderthal DNA, which humans have today and which has been cut up and spread out in tiny bits due to centuries of procreation. The differences provide a clue for a “molecular calendar,” according to Phys.org. The calendar has allowed Paabo and others to estimate that Neanderthals and Homo sapiens interbred 7,000 to 13,000 years before the Siberian individual lived – meaning no more than 60,000 years ago.
That gives a rough idea of when early humans went to Southeast Asia. “The ancestors of Australasians, with their similar input of Neanderthal DNA to Eurasians, must have been part of a late, rather than early dispersal through Neanderthan territory,” said Chris Stringer, professor at Britain’s Natural History Museum.