Ancient DNA research suggests that our non-African ancestors mixed with Neandertals about 50,000 years ago, resulting in one to two percent Neandertal DNA in non-African modern humans. In a study of 300 genomes, researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig and the University of California, Berkeley found that this likely occurred in a single instance about 47,000 years ago, suggesting a human migration out of Africa no later than 43,500 years ago. Some Neandertal variants likely helped humans adapt outside of Africa, while others, now absent among modern humans, were possibly removed soon after the admixture event.