The researchers analyzed the DNA of 13 Neanderthal men, women and children and found an interconnected web of relationships, including a father and his teenage daughter, another male relative of the father, and two second-degree relatives, possibly an aunt and her nephew. All Neanderthals were largely related, a consequence, the researchers believe, of the small Neanderthal population, with communities scattered over vast distances and numbering only about 10 to 30 people. Laurits Skov, first author of the study at the Max Planck Institute for Evolutionary Anthropology in Leipzig, said the fact that Neanderthals lived at the same time was “very exciting” and implied that they belonged to a single social community. Neanderthal remains have been recovered from numerous caves in western Eurasia – territory occupied by the heavy-browed humans from about 430,000 years ago until they disappeared 40,000 years ago. Previously it was impossible to say whether Neanderthals found at specific sites belonged to communities or not. “Neanderthal remains in general, and remains with preserved DNA in particular, are extremely rare,” said Benjamin Peter, senior author of the study in Leipzig. “We tend to get individuals from locations that are often thousands of kilometers and tens of thousands of years apart.” In the latest work, researchers including Svante Pääbo, who won this year’s Nobel Prize in medicine for innovative studies of ancient genomes, examined DNA from Neanderthal remains found in Chagyrskaya Cave and nearby Okladnikov Cave in the Altai Mountains of southern Siberia. Neanderthals had taken refuge in the caves around 54,000 years ago, seeking cover to feast on the ibex, horse and bison they hunted as the animals migrated along the river valleys the caves overlook. In addition to Neanderthal and animal bones, tens of thousands of stone tools were also found. Writing in the journal Nature, the scientists describe how ancient DNA shows that Neanderthals lived at the same time, with some being members of the same family. Further analysis revealed more genetic diversity in Neanderthal mitochondria – the tiny battery-like structures found inside cells that are passed down only through the maternal line – than in their Y chromosomes, which are passed down from father to son. The most likely explanation, the researchers say, is that Neanderthal women traveled from their home communities to live with male partners. Whether force is involved is not a question DNA can answer. “Personally, I don’t think there is particularly good evidence that Neanderthals were very different from early modern humans living at the same time,” Peter said. “We find that the community we are studying was probably very small, perhaps 10 to 20 people, and that the wider Neanderthal populations in the Altai Mountains were quite sparse,” Peter said. “Nevertheless, they managed to persist in a harsh environment for hundreds of thousands of years, which I think deserves a lot of respect.” Dr Lara Cassidy, assistant professor of genetics at Trinity College Dublin, called the study “landmark” as “the first genomic snapshot of a Neanderthal community”. “Understanding how their societies were organized is important for so many reasons,” Cassidy said. “It humanizes these people and gives rich context to their lives. But also, if we have more studies like this, it may also reveal unique aspects of the social organization of our own Homo sapiens ancestors. This is critical to understanding why we are here today and the Neanderthals were not.”
