Two years after they were tipped off by cavers plumbing the depths of the limestone tunnels in the Rising Star Cave outside Johannesburg, Berger and his team have discovered what they say is a new addition to our family tree.
The team is calling this new species of human relative “Homo naledi,” and they say it appears to have buried its dead – a behavior scientists previously thought was limited to humans.
“There is no damage from predators, there is no sign of a catastrophe. We had to come to the inevitable conclusion that Homo naledi, a non-human species of hominid, was deliberately disposing of its dead in that dark chamber. Why, we don’t know,” Berger told CNN. “Until the moment of discovery of ‘naledi,’ I would have probably said to you that it was our defining character. The idea of burial of the dead or ritualized body disposal is something utterly uniquely human.”
The first undisputed human burial dates to some 100,000 years ago, but because Berger’s team hasn’t yet been able to date naledi’s fossils, they aren’t clear how significant their theory is.
“Overall, Homo naledi looks like one of the most primitive members of our genus, but it also has some surprisingly human-like features, enough to warrant placing it in the genus Homo,” says John Hawks of the University of Wisconsin-Madison, a senior author on the papers describing the new species that were published Thursday.
Berger, a National Geographic Explorer-in-Residence, was already well-known for his discovery of “Australopithecus sediba,” another species of human ancestor, in 2008.
Marina Elliott, another of Berger’s astronauts, described the scene underground as “Some of the most difficult and dangerous conditions ever encountered in the search for human origins.”