The social organization of Neanderthal populations is not well understood. The latest research suggests that in Siberia at least, Neanderthals lived in groups of 10 to 20 people – similar to today’s mountain gorillas, which are an endangered species.
The study was led by a global team of scientists, including Svante Pääbo, a Swedish geneticist who won the Nobel Prize in Medicine this month for his work mapping our genetic links to Neanderthals.
Unlike many archaeological sites, which contain fossils accumulated over long periods of time, genetic studies of 11 Neanderthals found in Chagyrskaya Cave – in the Altai Mountains near the Russian border with Kazakhstan, Mongolia and China – showed that many of them were close relatives, suggesting they all lived around the same time.
“Chagyrskaya Cave is basically a moment in time 54,000 years ago when this community lived and died in this cave,” said Richard G. Roberts, a researcher at the University of Wollongong in Australia and one of the co-authors of the study. interview.
“Most archaeological sites, things build up slowly and tend to get chewed up by hyenas or something,” he said. “You don’t really get material-filled sites. It was filled with bones, Neanderthal bones, animal bones, artifacts. It’s a moment, literally frozen in time.
Scientists used DNA extracted from fossils found in Chagyrskaya Cave and two other Neanderthals found in a nearby cave to map relationships between individuals and search for clues to their way of life.
Chagyrskaya Cave is perched on a hill, overlooking a floodplain where herds of bison and other animals likely once grazed, Roberts said. Researchers found stone tools and bison bones buried in the cave alongside the remains.
Genetic data obtained from teeth and bone fragments showed that the individuals included a father and daughter, as well as a pair of second-degree relatives, possibly an aunt or uncle, niece or nephew, Roberts said. The father’s mitochondrial DNA – a set of genes passed from mothers to their children – was also similar to that of two of the other cave males, he said, indicating they likely had a common maternal ancestor.
“They’re so intertwined, it’s like a clan really lives in this cave,” he said. “The idea that they could last for generations and generations seems unlikely. I think they probably all died very close in time. Maybe it was just a horrible storm. They’re in Siberia, after everything.
The study also found that the genetic diversity of Y chromosomes (which are only passed down through the male line) was much lower than that of mitochondrial DNA in individuals, which the authors say suggests that females in Neanderthals were more likely to migrate than males. This pattern is also seen in many human societies, where women marry and move in with their husband’s family before having children.
Previous work by Pääbo, the Swedish geneticist, showed that Neanderthals intermixed with prehistoric humans after migrating out of Africa, and remnants of these interactions live on in the genomes of many people today. During the pandemic, he discovered that a genetic risk factor associated with severe cases of covid-19 was transmitted by Neanderthals, carried by about half of people in South Asia and about 1 in 6 people in Europe.
The authors state that the sample size of the latest study is small and may not be representative of the social life of the entire Neanderthal population.
“If only we could replicate [the study] in a few other places, then we would really have an idea of how Neanderthals lived their lives, maybe an indication of why they died out and we didn’t,” said Roberts, the Australian university. “We are so similar. So why are we the only ones left on the planet?”
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