When researchers looked at the genome of a Neanderthal from Siberia, they saw DNA that did not belong.
“No matter how we tried to fix it, it didn’t go away,” says Ilan Gronau, a computational biologist at Israel’s Herzliya Interdisciplinary Center. He was part of a team applying new methods of data analysis on previously studied genomes, and initially thought the unexpected DNA was a glitch. “[Then I thought] maybe this is real and maybe it tells an interesting story that just hasn’t been told until now,” he says.
That story was an undetected affair in human evolution.
We already knew that, after leaving Africa roughly 65,000 years ago, modern humans interbred with Neanderthals — it’s why most present-day humans have about 2 percent Neanderthal DNA. What Gronau and colleagues discovered, and published in Nature in February, is that Neanderthals also mated with our species some 50,000 years earlier.
They ...
