Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past

by David Reich

With this approach, we found that at least some Neanderthal-related genetic material came into the ancestors of present-day non-Africans eighty-six thousand to thirty-seven thousand years ago.20 We have since refined this date by analyzing ancient DNA from a modern human from Siberia who, radiocarbon dating studies show, lived around forty-five thousand years ago. The stretches of Neanderthal-derived DNA in this individual are on average seven times larger than the stretches of Neanderthal-derived DNA in modern humans today, confirming that he lived much closer to the time of Neanderthal mixture. His proximity in time to the mixing event makes it possible to obtain a more accurate date of fifty-four thousand to forty-nine thousand years ago.