Stephane 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 have not always been alone in this respect. 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’ve gotten a bad name as cave-dwelling thugs with batons, but Lauritz Skov, a paleontologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, says you really need to get that image out of your head.
“You know, this picture of Neanderthals being savages, is not entirely accurate,” he says. “The more we know about them, the more human-like they become.”
This human connection is reinforced by Skov and colleagues’ latest findings, which were published this week in the journal temper nature. The group looked at genetic material taken from Neanderthal bones and teeth from two caves in central Russia. The cave dwellers are believed to have lived about 55,000 years ago. They extracted DNA by drilling small holes in the ancient remains. It was a delicate process.
“One drop of my sweat would outnumber Neanderthal DNA molecules by a million to one or something, so you have to be really careful,” Skov says.
And it didn’t always work: sometimes DNA could not be found; Sometimes a prehistoric hyena would chew a bone, contaminating it. But Skov and his colleagues were eventually able to extract the genetic codes of 13 Neanderthals living in the cave, including several relatives: a father and teenage daughter, as well as a boy about 10 who was close to a woman. Inside the cave. (This “second-degree” relationship is a bit ambiguous, Skov says: “They could be like cousins, they could be grandparents/grandchildren, they could be an aunt/nephew, all those kinds of things.”).
It is the first time that Neanderthal relatives have been sequenced side by side. Skov says the DNA of the individuals living in the cave also provides some clues about how the community is organized. By looking at mitochondrial DNA, which is only passed on by females, and Y chromosomes, which come from males, Skov and his colleagues were able to determine that the women were more likely to be out-of-group. In other words, Neanderthal society may have been organized in such a way that women moved to be with the men’s family.
Lara Cassidy of Trinity College Dublin, Ireland, says the new discovery is significant because it is the first time that Neanderthals living at the same time have been sequenced. “It’s really exciting because what we have is a community, and we can begin to understand a little bit about how those communities work,” she says.
Cassidy, who was not a researcher in this study, cautions that the results are limited by the small number of Neanderthals sampled. There is no way to know, for example, whether women passed between all groups of Neanderthals, or whether this was something unique to this clan. She would like to know more about what connects the other people in the cave to each other. For example, humans build social groups of friends and unrelated friends.
“It looks like we’re able to pull ourselves together in all kinds of configurations,” she says. “It would be nice to know if Neanderthals were resilient.”
The genetic data is not good enough to know if everyone in the cave is related to distant relatives, relatives, or just friends. Skov says he’s still working to get a clearer picture.
There is another mystery: how did the father and daughter, the boy and his relatives die?
Skov says there is no clear evidence, but he suspects that starvation may have played a role.
“Life at that time was difficult, they survived the bullfighting,” he says. “You can imagine that in a year’s time, they weren’t able to hunt down everything they needed… something so sad.”
Perhaps these Neanderthals were the last humans. “That’s just 10,000 years before the Neanderthals went extinct,” Skov says. “There are very few left.”
But he says Neanderthals did not completely disappear. On average, non-African humans contain about 2% of Neanderthal DNA. In other words, it seems at least sometimes that humans and Neanderthals found each other, and built communities together.
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