Secrets of Ancient Human-Neanderthal Sex Revealed

Scientists have discovered that Neanderthal males had a preference for human females. Researchers have long known that Homo sapiens interbred with Neanderthals, who thrived across Europe and western Asia between about 400,000 and 40,000 years ago before going extinct. A trio of University of Pennsylvania scientists, writing in the journal Science, compared DNA from 73 modern women in Africa with genetic data from three female Neanderthals. They found the Neanderthals’ X chromosomes carried 62 percent more modern human DNA than the rest of their chromosomes. The skew points to a directional pattern in ancient sexual encounters—largely between male Neanderthals and female humans. “It’s a really interesting, provocative hypothesis that there was this long-term mating preference,” said Joshua Akey, a Princeton University geneticist who was not involved in the research. A male—who has an X and a Y chromosome—can pass on only one copy of the X chromosome, compared with a female with two. That dynamic, the authors said, helps explain why more modern human X chromosomes flowed into Neanderthal populations.




















