Stéphane de Sakutin/AFP via Getty Images
One of the things that makes us special as a species is our ability to form communities, but we humans haven’t always been alone in this regard. A new study sheds light on how Neanderthals built their own clans.
Neanderthals are distant cousins of humans who lived between 430,000 and 40,000 years ago. They have a bad reputation as cave-dwelling thugs with clubs, but Laurits Skov, a paleogeneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, says you really have to get that image out of your head.
“You know, this image of Neanderthals as brutes isn’t quite accurate,” he says. “The more we learn about them, the more they look like humans.”
This human connection is further reinforced by the latest findings from Skov and his colleagues, which were published this week in the journal Nature. The group examined genetic material taken from Neanderthal bones and teeth from two caves in central Russia. The cave dwellers are thought to have lived around 55,000 years ago. They extracted the DNA by drilling tiny holes in the ancient remains. It was a delicate operation.
“A drop of my sweat would exceed Neanderthal DNA molecules by a million to one or something, so you have to be very careful,” Skov says.
And it didn’t always work: sometimes the DNA couldn’t be found; sometimes a bone had been chewed by a prehistoric hyena, contaminating it. But Skov and his colleagues eventually managed to extract the genetic codes of 13 Neanderthals living in the cave, including several relatives: A father and his teenage daughter, as well as a boy of about 10 who was related to a woman. in the cave. (That “second-degree” relationship is a little fuzzier, says Skov: “They could be cousins, for example, they could be grandparents/grandchildren, they could be aunt/nephew, all those sorts of things.” ).
This is the first time that Neanderthal relatives have been sequenced side by side. Skov says the DNA of individuals living in the cave also provides clues as to how society might have been organized. By examining mitochondrial DNA, which is passed down only by women, and Y chromosomes, which come from men, Skov and his colleagues were able to determine that women were more likely to come from outside the group. In other words, Neanderthal society may have been organized in such a way that women moved to join men’s families.
Lara Cassidy of Trinity College in Dublin, Ireland, says the new discovery is significant because it is the first time Neanderthals living at the same time have been sequenced together. “It’s really exciting because we have a community, and we can start to understand a little bit about how those communities worked,” she says.
Cassidy, who was not a researcher in this study, warns that the results are limited by the small number of Neanderthals sampled. There’s no way to know, for example, if women moved between all groups of Neanderthals, or if it was something unique to that clan. And she would like to know more about what binds the other people in the cave. Humans, for example, build social groups of unrelated friends and companions.
“We seem to be able to come together in all sorts of configurations,” she says. “It would be nice to know if Neanderthals were that flexible.”
The genetic data isn’t good enough to see if everyone in the cave is a distant relative, or in-laws, or just friends. Skov says he’s still working on getting a clearer picture.
There is another mystery: how did the father and the daughter, and the boy and his parent, die?
Skov says there are no clear clues, but he suspects starvation may have played a role.
“Life back then was tough, they survived by hunting buffalo,” he says. “You can imagine if in a year they fail to hunt and catch everything they need… Something sad like that”
These Neanderthals were probably among the last of their kind. “That’s about 10,000 years before the Neanderthals went extinct,” Skov says. “There are very few left.”
But he says Neanderthals didn’t completely disappear. Non-African humans contain on average about 2% Neanderthal DNA. In other words, at least sometimes it seems, humans and Neanderthals found each other and built communities together.
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