Using several different methods of DNA analysis, an international research team has identified an interbreeding event between Neanderthals and modern humans that occurred an estimated 100,000 years ago, which is tens of thousands of years earlier than other such events previously documented. They suggest that some modern humans left Africa early and mixed with Neanderthals. These modern humans later became extinct and are therefore not among the ancestors of present-day people outside Africa who left Africa about 65,000 years ago.
"We knew from Neanderthal DNA found in the genomes of humans outside Africa that Neanderthals and humans have interbred. This interbreeding is estimated to have happened less than 65,000 years ago, around the time that modern human populations spread across Eurasia from Africa. We now find evidence for a modern human contribution to the Neanderthal genome. This is likely the result of much earlier interbreeding", says Sergi Castellano from the Max Planck Institute for Evolutionary Anthropology, who co-led the study.