Neanderthal–human baby-making was recent — and brief

Mixing between Neanderthals and Homo sapiens lasted less than 7,000 years — a remarkably short time considering that almost every living individual not of African ancestry carries a substantial amount of Neanderthal DNA. Researchers compared the genomes of individuals who lived between 2,200 and 45,000 years ago with those of modern people and found that the genetic intermingling started around 47,000 years ago. It ended around the time when Neanderthals went extinct.