Homo Naledi Raises Questions On Human Evolution
Over 1,500 human fossils belonging to some 15 individuals were uncovered in South Africa in 2015. The bones, belonging to young and old, male and female individuals, became among the richest assemblages of human fossils ever to be found. They were recovered from a deep chamber inside an underground cave system near Johannesburg and were said to belong to a new species called Homo naledi.
Scientific American noted that the discovery of the bones were best known for what researchers cannot figure out: their age. While the primitive characteristics suggested it was old, it has modern traits. Most of all, the condition of the bones showed that they are barely fossilized, hinting that the H. naledi may have lived more recently.
Now, however, pieces have fallen into place. In an article published in eLife, scientists reported that the H. naledi were actually young. To determine the age accurately, the team set up several labs independently and dated the samples without knowing the others' results. Using a variety of techniques, researchers determined the age of the original fossils to be between 236,000 and 335,000 years old.
According to The Washington Post, this means that H. Naledi actually roamed the Earth at about the same time that our own species was evolving. A discovery of a second caves also added evidence that these species may be more evolved. They have a modern behavior of burying their dead.
If the results are correct, this could indicate that Southern Africa may have played a more prominent role in human evolution. Before this discovery, scientists believed that east Africa was ground zero as far as human evolution was concerned. However, this change showed Southern Africa to have a more central role in forging the Homo species.
Experts not involved in the work expressed some doubts about the team's suggestion, though. Paleoecologist J. Tyler Faith, from the University of Queensland in Australia, noted that the diversity of mammalian species remains higher in East Africa. Faith added that if the dates of the found bones are correct, then "H. Naledi is a classic example of an evolutionary dead end."