"Members of our species had sex with Neandertals much earlier—and more often—than previously believed, according to a new study of ancient DNA. As some of the first bands of modern humans moved out of Africa, they met and mated with Neandertals about 100,000 years ago"
"By comparing the Neandertal genome with that of modern humans, they found a curious pattern: Present-day Europeans and Asians have inherited about 1% to 3% of their DNA from Neandertals, but Africans have not. This suggested that encounters between modern humans and Neandertals were rare and happened in the Middle East or the Arabian Peninsula after modern humans swept out of Africa, but before they spread widely. When moderns did expand all over Eurasia, they carried that Neandertal DNA in their cells"