Head start: Human 'ancestor' revealed
Published 09/04/2010 | 05:00
A REMARKABLY well preserved series of fossilised skeletons have been unearthed from a cave in South Africa and identified as a new ancestral species of ape-like hominid that could have been the direct ancestor of humans.
The species lived about 1.9 million years ago, walked on two legs and shared many other human features, but it also retained clear ape-like traits such as very long arms which showed that it had not yet made the complete transition from a life in the trees.
Researchers claimed yesterday that the species, named Australopithecus sediba, possesses such a mosaic combination of ape-like and human-like traits that it might belong to the group of "apemen" who evolved into the Homo genus Ä the human family.
The Homo genus came into existence around two million years ago, possibly evolving from the Australopithecines, the "southern apes" that lived in sub-Saharan Africa before this period. However, the paucity of the fossil record for this critical period in human history has cast doubt on exactly how the ape-to-human transition occurred.
Now, however, with the discovery of four skeletons belonging to Australopithecus sediba scientists believe they may have found the immediate ancestor of all subsequent species of Homo, from the primitive species such as Homo erectus and Homo habilis, to the anatomically modern Homo sapiens.
"We do feel that possibly sediba might be a Rosetta Stone for defining for the first time just what the genus Homo is," said Professor Lee Berger of the University of Witwatersand in Johannesburg, the leader of the study.
"In our team's opinion they fill a critical gap, lying between the Australopithecines and, most probably, the early members of the genus Homo; The skeletons are remarkable in their proportions and unseen before in the early hominid record," Professor Berger said.
Two of the partial skeletons, are described in the latest issue of the journal 'Science'.