The first snapshot of a Neanderthal community has been compiled by scientists who examined ancient DNA from bone fragments and teeth unearthed in caves in southern Siberia.
The researchers analyzed the DNA of 13 Neanderthal men, women and children and found a web of interconnected relationships, including a father and his teenage daughter, another male related to the father, and two second-degree relatives, possibly an aunt and his nephew.
All Neanderthals were highly inbred, a consequence, the researchers believe, of the small population size of Neanderthals, with communities scattered over great distances and numbering only 10 to 30 individuals.
Laurits Skov, first author of the study at the Max Planck Institute for Evolutionary Anthropology in Leipzig, said the fact that Neanderthals were alive 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, a territory that heavy-fronted humans occupied from about 430,000 years ago until they became extinct 40,000 years ago. Before, it was impossible to know whether Neanderthals found in specific places belonged to communities or not.
“Neanderthal remains in general, and remains with preserved DNA in particular, are extremely rare,” said Benjamin Peter, lead author of the study in Leipzig. “We tend to get single people from places often thousands of miles and tens of thousands of years apart.”
In the latest work, researchers such as Svante Pääbo, who won this year’s Nobel Prize in Medicine for groundbreaking studies of ancient genomes, examined DNA from Neanderthal remains found in Chagyrskaya Cave and nearby Okladnikov Cave in the Altai Mountains, southern Siberia.
Neanderthals took refuge in caves around 54,000 years ago, seeking shelter to feed on the ibex, horse and bison they hunted as the animals migrated through the cave’s river valleys. Beyond Neanderthal and animal bones, tens of thousands of stone tools were also found.
Writing in the journal Nature, the scientists describe how ancient DNA points to Neanderthals living at the same time, with some members of the same family.
Further analysis revealed more genetic diversity in Neanderthal mitochondria, the tiny battery-like structures inside cells that are passed down only through the maternal line, than in their Y chromosomes, which are passed down from the father to son The most likely explanation, the researchers say, is that Neanderthal women traveled from their home communities to live with male partners. However, whether force was involved is not a question that 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 study was probably very small, perhaps 10 to 20 individuals, and that the wider Neanderthal populations in the Altai Mountains were quite sparse,” said Peter. “However, they managed to persevere 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 a rich context to their lives. But then, if we have more studies like this, it can also reveal unique aspects of the social organization of our Homo sapiens ancestors. This is crucial for understand why we are here today and Neanderthals were not.”