From today’s Guardian:
A Neanderthal woman who lived and died in a Siberian cave 50,000 years ago has led researchers to the oldest known case of sex between modern humans and their beefy, thick-browed cousins.
Tests revealed that the female, whose remains were recovered from the Altai mountains on the Russia-Mongolia border, carried traces of DNA from Homo sapiens who appear to have mated with her ancestors 100,000 years ago.
The discovery pushes back - by tens of millennia - the date of the first known couplings between the two groups, and shows that both Neanderthals and modern humans inherited DNA from the prehistoric trysts.
Researchers have known since 2010 that people alive today carry as much as 4% Neanderthal DNA. The genetic legacy, which may affect human immune systems, and the risk of depression and even nicotine addiction, is a smoking gun for interbreeding that took place after modern humans left Africa 60,000 years ago and met up with the Neanderthals.