A species belonging to the human family tree whose remnants were first discovered in a South African cave in 2013 lived several hundred thousand years ago, indicating that the creature was alive at the same time as early humans in Africa, scientists said Tuesday.
A meticulous dating process showed that Homo naledi, which had a mix of human-like and more primitive characteristics such as a small brain, existed in a surprisingly recent period in paleontological terms, said Professor Lee Berger of The University of the Witwatersrand in Johannesburg. Berger led the team of researchers, which also announced that it had found a second cave with more fossils of the Homo naledi species, including a relatively well-preserved skull of an adult male.
The conclusion that Homo naledi was living between 236,000 and 335,000 years ago, and had not become extinct much earlier, shows that the human "Homo" family tree was more diverse than previously thought, said John Hawks of the University of Wisconsin-Madison and Wits University.
The name of Homo naledi refers to the "Homo" evolutionary group, which includes modern people and our closest extinct relatives, and the word for "star" in the local Sotho language. The fossils were found in the Rising Star cave system, which includes more than 2km of underground, mapped passageways. The second chamber containing the more recent fossil discoveries is more than 100 meters from the cave where the original discoveries were made, and publicly announced in 2015.
Berger, the research team leader, said the discovery of a second chamber with Homo naledi remains gives more credence to the idea that the species deliberately disposed of its dead in pitch-black caves that are extremely difficult to reach. However, some experts who were not on the research team questioned whether the small-brained species was capable of such behavior and speculated that other ways to access the chambers may have existed in the past.
The new discoveries offer a unifying message that counters populism, intolerance and ethnic prejudice sweeping many parts of the world, said Adam Habib, vice-chancellor of the University of the Witwatersrand.