Evidence of Prehistoric Massacre May Indicate Warfare Among Hunter-Gatherers

War seems to be an inescapable part of human history, and it's certainly a reality of the present day. But it's not exactly clear when the practice of warfare began. Many researchers believe it originated in tandem with agriculture and the rise of settled societies that owned property and goods.

The findings of a team working in Kenya, however, might indicate that groups of primarily nomadic hunter-gatherers engaged in war, too. Researchers from Cambridge University's Leverhulme Centre for Human Evolutionary Studies have discovered portions of more than two dozen human skeletons at a site called Nataruk, 30 kilometers west of Lake Turkana, that date back roughly 10,000 years. Among them were 12 nearly complete skeletons, ten of which showed ample evidence of a violent death by way of weapons. The findings are featured on the cover of Wednesday's issue of the journal Nature.

"The remains from Nataruk are unique, preserved by the particular conditions of the lagoon with no evidence of deliberate burial," reads the paper's introduction. "They offer a rare glimpse into the life and death of past foraging people, and evidence that warfare was part of the repertoire of inter-group relations among some prehistoric hunter-gatherers."

The Cambridge team discovered the Nataruk site in 2012, says Marta Mirazon Lahr, a paleoanthropologist who led the work published in Nature. The researchers had identified what they believed was the shore of an ancient lagoon and began searching for fossils. It wasn't long before one of the field assistants came back and said, "I've got bones for you."

What first appeared to be the back of a skull turned out upon excavation to be not only a whole head, but also a full skeleton. That first skull, which showed major injuries, is the one pictured on the cover of Nature, Mirazon Lahr tells Newsweek. Next, the broken ends of two legs became another nearly complete skeleton, and it had a piece of obsidian, a very sharp stone, still stuck to the side of its head.

All together, the team found remains of at least 27 individuals, including men, women, half a dozen young children under the age of 6 and one young teenager. One of the women was discovered with the bones of a fetus between six and nine months old in her abdominal cavity. The various injuries sustained appear to been caused by four different types of weapons, Mirazon Lahr says, including arrows shot from a distance, clubs and some type of club with small blades inserted into it.

It took the intervening years since the bones were first excavated to do the requisite preservation work in conjunction with the Turkana Basin Institute in Nairobi, and to try various methods to date the finds, which the researchers ultimately concluded were between 9,500 and 10,500 years old.

The paper published Wednesday explains that "the origins of war are controversial," and that "researchers remain deeply divided as to whether antagonistic relations formed a significant element of social life in prehistory."

Mirazon Lahr believes her team's discovery is indicative of a planned attack by one group of mostly nomadic hunter-gatherers on another. The bodies were scattered around the site and their positioning, along with the types of weapons used and the injuries sustained, suggest they remained where they fell after an attack by a group from a different area, and were preserved by the sediments of the lake, she says.

Theories of warfare often center around concepts like property—land, food and other items found in settled communities—and later on power, religion and other ideas. So the notion that these nomadic groups might have engaged in violent conflict would mean there was something else they considered worth fighting for, Mirazon Lahr explains. Perhaps, she says, it was access to this fertile portion of the shore and the animals that congregated there.

The paper compares this discovery to a find of 58 bodies in the Qadan graveyard at Jebel Sahaba in Sudan that date back 12,000 to 14,000 years, with 23 bodies showing signs of violence. But those were buried in an organized fashion in a cemetery, indicating a village was nearby.

"There's no other find like it," Luke A. Glowacki, a postdoctoral researcher in human evolutionary biology at Harvard University who was not a part of the discovery, told The New York Times. It "shows warfare occurred before the invention of agriculture."

Not everyone is so quick to come to a similar conclusion. Douglas P. Fry, a professor of anthropology at the University of Alabama, told the Times that he would want to see additional types of evidence—such as fortifications, specialized weapons of war and artistic or symbolic depictions of warfare—and in more than one location before concluding foragers during this period engaged in the practice.

Mirazon Lahr says she's heard several people express dismay that the discovery shows that people have always been violent. But she believes that's only one part of the story. "We're very clearly capable of nasty, violent things—you read about it in the newspaper every day," she says. "What makes people different from chimpanzees and other animals is that we can do things for the benefit of others that are not necessarily in our interest. Altruism is also in our nature, and we shouldn't forget it."