Present-day chimpanzees are humans' nearest living relatives and where the last chimp-human common ancestor lived is a central and highly debated issue in palaeoanthropology. Their findings, published today in two papers in the journal PLOS ONE, further indicate that the split of the human lineage occurred in the Eastern Mediterranean and not - as customarily assumed - in Africa. Credit: Wolfgang Gerber, University of Tübingen

The common lineage of great apes and humans split several hundred thousand years earlier than hitherto assumed, according to an international research team headed by Professor Madelaine Böhme from the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen and Professor Nikolai Spassov from the Bulgarian Academy of Sciences. The team, led by academics from the Senckenberg Centre for Human Evolution and Palaeoenvironment, the University of Tübingen and the Bulgarian Academy of Sciences, announced the discovery after analysing two specimens of the fossil hominid Graecopithecus freybergi. Using computer scanning, they were able to visualise the internal structures of the fossils and demonstrated that the roots of premolars are widely fused. Professor Madelaine Böhme, who led the study, said: 'While great apes typically have two or three separate and diverging roots, the roots of Graecopithecus converge and are partially fused - a feature that is characteristic of modern humans, early humans and several pre-humans including Ardipithecus and Australopithecus.' Credit: Wolfgang Gerber, University of Tübingen

The lower jaw, nicknamed 'El Graeco' by the scientists, has additional dental root features, suggesting that the species Graecopithecus freybergi might belong to the pre-human lineage. "We were surprised by our results, as pre-humans were previously known only from sub-Saharan Africa," Jochen Fuss, a doctoral student at the University of Tübingen in Germany who conducted this part of the study, said in a press release. An analysis showed that the Graecopithecus fossils were 7.24 and 7.175 million years old – several hundred thousand years older than the oldest potential pre-human from Africa, the six to seven million year old Sahelanthropus from Chad. Professor David Begun, a University of Toronto paleoanthropologist and co-author of this study, added, "This dating allows us to move the human-chimpanzee split into the Mediterranean area." Environmental changes may have helped drive the evolution of pre-human species, separate from apes, said co-author Madelaine Bohme, a professor of human evolution at the University of Tubingen. Based on analyses of the sediments in which the two fossils were found, the researchers found that the North African Sahara desert originated more than seven million years ago. "In summary, we reconstruct a savannah, which fits with the giraffes, gazelles, antelopes, and rhinoceroses that were found together with Graecopithecus," Spassov added

"The incipient formation of a desert in North Africa more than seven million years ago and the spread of savannahs in Southern Europe may have played a central role in the splitting of the human and chimpanzee lineages," said Böhme.
Scientists discover 7.2 million-year-old "pre-human" remains in the Balkans area near Bulgaria and Greece.