Telltale evidence of ancient liaisons with Neanderthals and other extinct human relatives can be found in the DNA of billions of people.
Geneticist David Reich and his colleagues estimate that the DNA of living Asians and Europeans is, on average, 2.5 percent Neanderthal. The interactions probably happened across the area inhabited by Neanderthals.
David Reich, a geneticist at the Harvard Medical School, has redrawn our species’ family tree. And today, in his office overlooking Avenue Louis Pasteur in Boston, he picks up a blue marker, walks up to a blank white wall, and shows the result to me. He starts with a pair of lines—one for humans and one for Neanderthals—that split off from a common ancestor no more than 700,000 years ago. [...] DiscoverMagazine.com