
When human ancestors dispersed out of Africa over 50,000 years ago, they encountered Neanderthals that already carried some of their genes.
Today we are the only human species in the world, but it wasn’t always like that. Four hundred thousand years ago, when Homo sapiens’ ancestors lived in East Africa, Neanderthals already lived in Eurasia. When the only way to get around is on foot, that is literally worlds apart. Nevertheless, 50,000 years ago H. sapiens arrived in Europe, and Neanderthals disappeared. An unlucky coincidence? Killed by our ancestors? The subject has long been debated.
In 2010, the Neanderthal genome was sequenced and traces of their DNA were found in modern human genomes, suggesting a story of (maybe even…