Possibly oldest to bury dead, Homo naledi may be stepping stone in human evolution
Caring for each other both in life and death is one of the behaviours which makes us human. The legacy of this behaviour may now be pushed back by up to two million years, according to a discovery which may revolutionize our understanding of human evolution. A new species of human recently discovered in a South African cave is likely the oldest member of genus Homo, the only surviving member of which is us modern humans, Homo sapiens.
This new human species has been dubbed Homo naledi, named after the word for “star” in Sotho, a language spoken in South Africa. Over 1,500 fossil bones from at least 15 individuals of Homo naledi were discovered in a cave in the Cradle of Humankind, a UNESCO World Heritage Site about 50 km north of Johannesburg.
Homo naledi appears to capture a critical moment of transition in human evolution. Humans of genus Homo are believed to have evolved from a member of Australopithecus, an earlier genus of humans that went extinct about two million years ago. Homo naledi has features which define it unambiguously as a more modern human of genus Homo, but also has anatomical features similar to earlier human species in Australopithecus.
While anthropologists and biologists are hailing the evolutionary implications of Homo naledi’s discovery as a milestone, the fossils’ settings may also revolutionize our understanding of ancient human behaviour. The location of these fossils in the Rising Star cave system rules out any possibility that they could have gotten there naturally, meaning Homo naledi ritually brought their deceased to this cave as a final resting place. The cave in particular is 80 meters from the system’s entrance and is completely dark without artificial light, meaning Homo naledi must also have had fire to guide them through it. This makes Homo naledi one of the few species of human known to bury their dead, and possibly the oldest known to do so.
The size of this find makes it the largest assemblage of extinct human remains discovered in Africa to date. The completeness of the skeletons recovered from this cave is also largely unparalleled in discoveries of ancient human remains, many of which are of single bones or bone fragments.
The fossils from this discovery have not yet been directly dated, however their anatomy suggests they may have lived as far back as two million years ago. If Homo naledi proves to have lived this far back, it would become the oldest member of genus Homo identified by more than just a fragment of bone, deepening our understanding of how we have evolved. If Homo naledi proves to be much younger, it would show that multiple species of Homo humans co-existed at the same time and would also shed light on what led us Homo sapiens to evolve.
Homo naledi’s discovery was announced on Sept. 10 in two papers published on the online open-access journal eLIFE. The papers were led by Lee Berger and Paul Dirks of the University of Witwatersrand in Johannesburg, and James Cook University in Townsville, Australia, respectively, and included a team of over 45 co-authors. The research behind the discovery received significant funding from the National Geographic Society, as well as from various South African government bodies and other funders.
