The first snapshot of a Neanderthal community has been pieced together by scientists who examined ancient DNA from bone and tooth fragments unearthed in caves in southern Siberia.
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 man related to the father, and two second-degree relatives, possibly an aunt and nephew.
All the neanderthals they were strongly 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 from the Max Planck Institute for Evolution 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, territory that bushy-browed humans occupied from about 430,000 years ago until they became extinct 40,000 years ago. Previously, it was impossible to know whether Neanderthals found at particular sites 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 individuals from sites often separated by thousands of kilometers and tens of thousands of years.”
In the latest work, researchers like Svante Pääbo, who won this year’s prize Nobel Prize in Medicine for groundbreaking studies on ancient genomes, he examined DNA from Neanderthal remains found in Chagyrskaya Cave and nearby Okladnikov Cave in the Altai Mountains of southern Siberia.
Neanderthals took refuge in the caves some 54,000 years ago, seeking shelter to feast on the mountain goats, horses and bison they hunted as the animals migrated along the river valleys that overlook the caves. Beyond animal and Neanderthal bones, tens of thousands of stone tools were also found.
Writing in the journal Naturescientists describe how ancient DNA points to Neanderthals living at the same time, and some were members of the same family.
Further analysis revealed greater genetic diversity in Neanderthal mitochondria, the tiny battery-like structures inside cells that are only passed down the maternal line, than in their Y chromosomes, which are passed 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. However, whether force was involved is not a question DNA can answer. “Personally, I don’t think there’s any particularly good evidence that Neanderthals were very different from early modern humans who lived at the same time,” Peter said.
“We found that the community we studied was probably very small, perhaps 10 to 20 individuals, and that the broader Neanderthal populations in the Altai Mountains were quite sparse,” Peter said. “However, they managed to persevere in a difficult environment for hundreds of thousands of years, which I think deserves great respect.”
Dr Lara Cassidy, assistant professor of genetics at Trinity College Dublin, called the “landmark” study “the first genomic snapshot of a Neanderthal community”.
“Understanding how their societies were organized is important for many reasons,” Cassidy said. “It humanizes these people and gives a rich context to their lives. But also, later on, if we have more studies like this, it may also reveal unique aspects of our own social organization. Homo sapiens ancestors. This is crucial to understanding why we are here today and Neanderthals were not.”
