Fresh analysis of a 2 million-year-old hominid fossils discovered in 2008 has led to the realisation that tool making ability came from species existing much before our genus — Homo. This makes Australopithe-cus sediba, not only the
predecessor from which the Homo genus evolved but also our direct tool-making ancestor, taking the “handyman” crown from more modern Homo habilis (existed 1.75 million years ago).
The middle-aged female plus male child fossils, named MH1 and MH2, were found very well preserved north of Johannesburg, with a complete hand and undistorted pelvis; skull fragments and pieces of feet never seen before in early hominids were also found.
Hand features read by the palaeontologists suggest their use for both arboreal (climbing tress) locomotion as well as manipulative ability essential for making and using tools. Au. Sediba’s long thumb, small fingers and human-like precision grip makes it a better candidate for early tool making than the Homo habilis, first among the Homo genus.
This opposing chronology has confused scientists, although some say “there must have been various hominins with various types of hands producing tools during the same time period.”
“The hand is one of the very special features of human lineage, as it is very different from the hand of the apes. Apes have long fingers for grasping branches or for use in locomotion, and thus relatively short thumbs making it very difficult for them to grasp like a human.
Au. sediba has, in contrast, a more human-like hand that has shortened fingers and a very long thumb, although, at the same time it appears to have possessed very powerful muscles for grasping,” says Professor Lee Berger, who discovered the fossils and also leader of Sediba Project.
When put together, features of Au. sediba’s pelvis, brain and foot also indicate its existence at the midrange between modern humans and early hominids.
As far as use of stone tools goes, all of these fossils are post-dated, meaning tools appeared much before they existed.
However, unavailability of intact fossils make it difficult to point out the first tool using hominid; it is likely that such a species hasn’t been discovered yet. It is still important to know how and where the features we posses today developed from.
For example, Au. Sediba was found to have “advanced but small” brain, proving that brain became sophisticated before it got bigger in size. Leading journal Science published five papers on this analysis on Thursday.