New Human-Like Species Discovered
Discovering an entirely new hominin species is a rare event. Discovering a mother-lode of 15 individual skeletons in one location in Africa is unprecedented.
The new species has been named Homo naledi and was “discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa.”
The new species is an interesting mix of some modern and some primitive features. Its hands and legs were more similar to a modern human than other hominins of the time. Its body and cranial capacity, however, were more similar to Australopithecines, which predate the Homo genus.
This mixture of features is what we expect to find – hominins represent a bushy and complex branching of many lines, only one of which eventually led to modern humans. Evolution is not a straight line, and so you cannot place every species into a single sequence. “Modern” and “primitive” are relative terms, and usually defined with respect to an ultimate surviving species, in this case us. Many branches are therefore likely to have a mixture of relatively modern and relatively primitive features of the reference branch.
The picture of human evolution that has been emerging over the last few decades has been more and more complex, and this new piece to the puzzle adds further complexity.
The fossils have yet to be dated, but the researchers estimate they are from between three and two million years ago – from around the first appearance of the genus Homo. The oldest Homo species currently known is habilis, dating from 2.8 to 1.5 million years ago. Nadeli may be a bit older.
Homo naledi now joins other Homo species in our family tree: habilis, erectus, ergaster, rhodesiensis, antecessor, heidelbergensis, floresiensis, neanderthalensis, and sapiens. There are also a few putative species that may just be subspecies. Floresiensis, also known as the “Hobbit,” is also still a bit controversial. Naledi is closer to the base of the Homo branch, but its exact placement is uncertain.