Ancient Human Relatives May Have Buried Their Dead

The ritual of burying the dead could be much older than thought: In South Africa’s Rising Star cave system, paleontologists found what they say is a burial site of our ancient ancestors, Homo naledi, according to new research.

If confirmed, it would mean these extinct human relatives intentionally buried their dead long before Homo sapiens did. Previously, only humans and Neanderthals have been known to bury their dead.

The study was posted on the preprint server bioRxiv on Monday. This and two other papers describing the findings are currently under peer review at the journal eLife, a journal spokesperson tells the New York Times’ Carl Zimmer.

Rick Potts, a paleoanthropologist at Smithsonian’s National Museum of Natural History who was not involved with the study, isn’t yet convinced by the findings. “There’s still a lot to uncover,” he tells Maddie Burakoff of the Associated Press (AP).

However, other scientists are more persuaded by the new research. “I might have been one of those people who’s been skeptical about the idea that a small-brained creature like Homo naledi could be going deep into the cave to dispose of its dead,” Chris Stringer, an anthropologist at the Natural History Museum in London who did not participate in the research, tells National Geographic’s Kristin Romey. “But I have to say, on the amount I’ve seen so far, that yes, it does change my view on the balance of probability.”

The fossils of H. naledi, first discovered in South Africa in 2013, date to between 236,000 and 335,000 years ago. Meanwhile, the oldest known human burial site dates to around 78,000 years ago. So, burials of H. naledi in Rising Star would predate the earliest human burials by about 160,000 years or more.

H. naledi were a type of hominin, a group of species that includes modern humans and our extinct ancestors. The species walked upright on two legs, stood about five feet tall and had curved fingers and toes, writes the Agence France-Presse (AFP). But notably, H. naledi had brains around a third of the size of ours, making it even more surprising to scientists that they might have buried their dead.

“This is something that takes a lot of time and effort to do,” Lee Berger, a paleoanthropologist at the University of Witwatersrand in South Africa who led the research, tells the AP.

Still, several characteristics of the cave site point to the burials being intentional, writes the team in the paper. For instance, the layers of sediments were disrupted in a way that suggested the early hominins had dug and filled holes. Some of the bones were in oval-shaped depressions, with a layer of mud around the holes, but not inside of them, writes the New York Times. This signaled to the researchers that the remains hadn’t just sunken into the sediment under their own weight.

“What you are seeing here is a repeated ritual, a response to the dead that has meaning,” Berger tells the Washington Post’s Mark Johnson.

But Aurore Val, a zooarchaeologist at the French National Center for Scientific Research who was not involved in the study, tells the Post that the findings don’t rule out other possibilities for how the bones ended up there, such as rain or mudflow carrying them from another part of the cave.

Additionally, a lot of the bones are disconnected and spread out in a way that “can’t be explained by the natural course of decomposition,” María Martinón-Torres, a paleoanthropologist at University College London who did not contribute to the findings, tells National Geographic.

In another preprint paper, the team describes engravings on the cave walls, which they claim were made by H. naledi. “That would mean not only are humans not unique in the development of symbolic practices, but may not have even invented such behaviors,” Berger tells the AFP.

But since the researchers have not dated the engravings yet, it’s possible a different species, such as modern humans, made them, Potts tells the AP.

Taken together, the discoveries of the possible burial site and the cave engravings could mean that having a larger brain is not necessary for complex thought, write the researchers in their third preprint paper.

“Big brains are still important,” says study co-author Agustín Fuentes, an anthropologist at Princeton University, to the AP. “They just don’t explain what we thought they explained.”

Will Sullivan | | READ MORE

Will Sullivan is a science writer based in Washington, D.C. His work has appeared in Inside Science and NOVA Next.