Recent dating evidence re-establishes the Kibish fossils found in Ethiopia as the oldest modern human fossils known, at about 195,000 years.
The Kibish (Omo) fossils were found in 1967 in the Kibish region near the Omo River in Ethiopia. A partial skull and skeleton (Omo 1) and a skull lacking its face (Omo 2) were discovered in separate localities and dating techniques available at the time suggested they might be about 130,000 years old.
In 2003 two partial and one nearly complete modern human skulls were found in Herto, Ethiopia, and were dated at about 160,000 years old. They were hailed as the oldest relatively complete and well-dated finds of our species Homo sapiens.
However, volcanic sediments just below the level of where the Omo fossils were found, have been dated by an argon isotope method to about 196,000 years. Further dating and fossil evidence suggests that the Omo skulls are only slightly younger than this determined age - about 195,000 years old. If correct, this re-establishes the position of Omo 1 as the oldest clearly modern human fossil.
Additionally, these findings give support to the idea that our species Homo sapiens originated in Africa, with modern people subsequently spreading out from there (the Out of Africa theory). Previously, hard evidence from fossils and dating techniques had always been hard to find.
Although most workers now accept we originated in Africa within the last 300,000 years,' says Chris Stringer, Natural History Museum human origins expert, 'there is still much uncertainty about how, when and where this origin occurred.’
The Omo and Herto finds confirm that East Africa was a key area in this story and now has the oldest clear evidence of modern human origins.'
'However, archaeological finds from southern Africa suggest that region may have played an important part in the development of modern human behaviour, also part of what defines us as a species. So we will need further evidence from the whole continent to build up a complete picture of how our species began.'
'Nevertheless the new dating confirms the place of the Omo fossils as landmark finds in unravelling our origins.’
This research is published in the journal Nature .