The DNA from a Neanderthal family offers new information on this species

Chagyrskaya Cave (Photo ©Bence Viola. All rights reserved)
Chagyrskaya Cave (Photo ©Bence Viola. All rights reserved)

An article published in the journal “Nature” reports the results of a genetic study on a Neanderthal community that lived in today’s Siberia. A team of researchers including Nobel Prize winner for medicine Svante Pääbo obtained DNA from 11 individuals who lived in Chagyrskaya Cave and 2 who lived in Okladnikov Cave. It’s one of the largest genetic studies on Neanderthals ever done. The results of the genetic analysis indicate that some of the inhabitants of Chagyrskaya Cave were closely related, including a father and daughter.

This study is the latest in a series that is slowly reconstructing the history not only of Homo sapiens but also of Neanderthals and Denisovans, of which only a few bones have been identified so far. Siberia is an area where many human bones belonging to these three species have been found, sometimes to individuals that were the result of interbreedings. The analyzes also offered a lot of information on the migrations of groups belonging to these species.

This is possible thanks to advances in paleogenetics, the branch of genetics that studies the DNA of extinct species. Svante Pääbo’s great merits in these developments earned him the Nobel Prize in Medicine in 2022.

Reconstructions made in previous studies indicate that Neanderthals lived in the Caves of the Altai Mountains starting around 120,000 years ago. Over the millennia, there were migrations of various groups and encounters between different groups but this study indicates that the Neanderthals identified in Chagyrskaya and Okladnikov Caves were not descendants of the previous ones but were more closely related to other European groups such as that of Vindija Cave in today’s Croatia. This confirms the conclusions of archaeologists based on the similarities between the stone tools produced by the various groups.

Of the 13 identified Neanderthals, 11 in Chagyrskaya Cave and 2 in Okladnikov Cave, 7 were men and 6 women, 8 adults and 5 children or teenagers. Mitochondrial DNA also showed various cases of heteroplasmy shared between different individuals. This type of genetic variant is passed from mother to child and usually persists for less than three generations. Its sharing indicates that individuals are closely related maternally.

Hundreds of thousands of animal remains and stone tools have been discovered in Chagyrskaya and Okladnikov Caves. Animal remains indicate that these groups of Neanderthals hunted ibex, horses, and bison that lived in the valleys of the area and collected raw stones for their tools in areas even tens of kilometers away.

The different groups, which included between 10 and 20 individuals, were related mainly thanks to the women moving from their birth group. The researchers discovered that by finding much greater variability in mitochondrial DNA, passed from mother to children, compared to that of the Y chromosome, passed from father to children.

Another reason for interest in the Neanderthals discovered in this study is that they constitute the easternmost community found so far for this species. They lived about 100 kilometers from Denisova Cave but their DNA shows no interbreedings with the species discovered in that cave. Also for these reasons, the researchers are looking for more genetic traces of Neanderthals in the various areas of Eurasia to keep on reconstructing their history.

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