Homo naledi was very different from archaic humans that lived around the same time. Left: Kabwe skull from Zambia, an archaic human. Right: ''Neo'' skull of Homo naledi.
In 2013, researchers in South Africa found the remains of a previously-undiscovered human species. In 2015, they introduced Homo naledi, a human with a tiny brain, ape-like shoulders, but other features that were more human. Where would this species fit in the homo family tree? A big step would be to date the fossils. Using several different methods, a team from the University of Witwatersrand led by paleoanthropologist Lee Berger has determined Homo naledi to be between 236,000 and 335,000 years old, much younger than such a primitive human should be -even younger than Homo erectus.
If these dates hold, it could mean that while our own species was evolving from other, large-brained ancestors, a little-brained shadow lineage was lingering on from a much earlier period, perhaps two million years ago or more. The proposed age range for the fossils also overlaps with the early Middle Stone Age, fueling a provocative, though unproven, possibility: that the stone-tool record in South Africa from that time wasn’t just the handiwork of anatomically modern humans.the latest research on Homo naledi at National Geographic News.
“How do you know that these sites that are called [examples of] the rise of modern human behavior aren’t being made by Homo naledi?” says Berger, who is also a National Geographic explorer-in-residence. “You can imagine how disruptive that could be.”