Javier Baena Preysler

An article published in Nature shows that the last Neanderthals in northwestern Europe exhibited greater genetic variability than previously thought, which, according to the authors, could call into question the idea that this was one of the causes of their extinction. The study included genetic data from 27 Neanderthals dating back about 52,500 years, found at ten sites in France and Belgium. The genome of a 45,000-year-old Neanderthal found in Belgium was also sequenced. According to the results, these Neanderthals lived in large, well-connected groups, as they showed no signs of inbreeding. Although they temporarily coexisted with early modern humans in that region, the study found no evidence of interbreeding with them.

When Neanderthals and modern humans had offspring together, little Neanderthal DNA from the X chromosome entered the human gene pool. A study published in the journal Science traced ancient gene flow and found a relative excess of 62% modern human ancestry on Neanderthal X chromosomes. This suggests that the couples who had children were mostly Neanderthal men and modern human women, although the authors cannot rule out the possibility that demographic processes played a significant role.