A preference for pairings between male Neanderthals and female Homo sapiens may answer the question of why there are "Neanderthal deserts" in human chromosomes.

Most people alive today carry fragments of Neanderthal DNA in their genome. Now scientists are gaining a more intimate understanding of the ancient encounters that put it there.

Learn how sex-biased interbreeding between Neanderthals and modern humans explains why Neanderthal DNA is largely missing from the X chromosome.

A study shows that interbreeding between the two species occurred primarily in one direction, and the origin of this bias is still unclear

Analysis of Neanderthal DNA revealed that the male Neanderthals regularly bred with female Homo sapiens, but this cross-species affection did not apply to male Homo sapiens and Neanderthal women. The study looked at the X chromosome of Neanderthals and found more human DNA than expected.