Ancient DNA unveils Siberian Neandertals’ small-scale social lives

DNA from a group of Neandertals who lived together and a couple of others who lived not far away has yielded the best genetic peek to date into the social worlds of these ancient hominids.

As early as around 59,000 years ago, Neandertal communities in a mountainous part of Central Asia consisted of small groups of close relatives and adult female newcomers, researchers report October 19 in Nature.

That social scenario comes courtesy of DNA extracted from the teeth and bones of 13 Neandertals found at two caves in the foothills of southern Siberia’s Altai Mountains. Estimates of overall genetic similarity among these Stone Age folks indicate that they formed communities of about 20 individuals, with females often migrating from their home groups to those of their mates, say evolutionary geneticist Laurits Skov of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues.

It’s unknown whether Altai Neandertals’ small-scale lifestyle was unusual, perhaps due to living in a sparsely populated area, or mirrored Neandertal practices elsewhere in Asia and Europe. Large numbers of Neandertals in Central Europe transformed a forest into grassland around 125,000 years, suggesting they could scale up communities when needed (SN: 12/15/21).

Skov’s group studied the DNA of 11 Neandertals from Chagyrskaya Cave and two Neandertals from Okladnikov Cave (SN: 1/27/20). The Chagyrskaya individuals included a father and his teenage daughter as well as an adult female and an 8- to 12-year-old boy, who was possibly her nephew or grandson.

In the Chagyrskaya group, mitochondrial DNA, typically inherited from the mother, displayed greater diversity than DNA from the Y chromosome, which is inherited only by males. The enhanced mitochondrial DNA variety suggests that adult females frequently moved into that community while the males stayed put, the researchers suspect.