New species of archaic humans seem to pop up pretty frequently these days. If you accept the evolution by natural selection model, then the human lineage is less of a linear progression from primate ancestors, and more of a messy demolition derby of sub-species which came and went, branching out into dead-end alleys of development. Only one line survived the ravages of the last few hundred thousand years – us. The remains of the rest, the human species which didn’t make it and succumbed to extinction, like Homo floresiensis, are being dug out of caves around the world.
The latest of these discoveries are the Homo naledi hominins, who appear to have lived in southern Africa some 300,000 years ago around the same time that early humans were emerging as a species (1). The remains of these hominins was discovered in the complex Rising Star system of caves in South Africa a couple of years ago (2). The bones littered a pit-like chamber which was very difficult to access. The bones provide palaeontologists with a curious set of archaic specimens. The small skull size of Homo naledi, providing space for a brain just half the size of a modern human, indicated a primitive hominin.
The small brain size led the palaeontology team, led by the maverick academic Lee Berger, of Johannesburg’s University of the Witwatersrand, to conclude that the species had lived perhaps 2 – 3 million years ago. The shape of the skull was suggestive of early Homo species, including Homo erectus, Homo habilis or Homo rudolfensis. However, various aspects of the skeleton more closely resembled modern humans – their wrists, the feet, the lower part of the pelvis, some of their teeth (3). It’s a very odd mix indeed:
““You could almost draw a line through the hips—primitive above, modern below,” said Steve Churchill, a paleontologist from Duke University. “If you’d found the foot by itself, you’d think some Bushman had died.”” (2)