THIS year is shaping up to be a good one for human palaeontology. Two weeks ago, on March 24th, what appears to be an entire new species of human was announced on the basis of the DNA preserved in a single finger bone from Siberia. Now, another manlike species has been described using more traditional evidence, from a more traditional source of ancient human remains: Africa.
The new species, dubbed Australopithecus sediba, is reported in Science this week by Lee Berger and his colleagues at the University of the Witwatersrand, in Johannesburg. It is represented by the fragmentary remains of two skeletons found in caves at a site called Malapa, in South Africa. As a member of the genus Australopithecus, sediba is less manlike than the as-yet-unnamed Siberian discovery, which was a member of the genus Homo. Palaeoanthropologists are nevertheless excited because some of its features, particularly the shape of its pelvis (which would have made upright walking more efficient) and the size of its teeth (which were smaller than those of its ancestors), have a lot in common with members of Homo. At a bit less than 2m years of age, the new skeletons seem to be younger than the oldest known representatives of Homo, and therefore cannot be directly ancestral to that genus. Nevertheless, these features suggest to some that an ancestor of A. sediba was also an ancestor of Homo, and thus of modern humanity.
That is still a guess. Human fossils, particularly of such an age as this, are rare in the extreme—so rare that each new discovery has a tendency to rewrite the history books. Nor is there the remotest possibility of extracting useful DNA from the new fossils. They are too old and Africa is too hot for significant traces of the molecule to have survived. But some new evidence has been added to the ascent of man, and that is always welcome.