Our ancient human ancestors may not have split from chimpanzees in the grasslands of East Africa, but in Europe instead. Researchers analyzing fossils of an ancient species of ape discovered in Greece and Bulgaria claim to have found evidence that the two lineages had already diverged by the time it was alive in the Mediterranean, upending what we traditionally thought.
It all hinges on the fossils of an ancient ape known as Graecopithecus freybergi. Known from two separate fossils of teeth and partial jaws discovered in the Balkans, the researchers are arguing that the morphology of these teeth show that chimps and humans had already split in Europe some 7.2 million years ago.
“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,” explained Professor Madelaine Böhme, who led the research published in PLOS ONE. This, she suggested, shows that our lineage had already diverged from that of chimpanzees hundreds of thousands of years before it was thought to have occurred in Africa.
The history of our species, and apes in general, is complicated and controversial. There are thought to be around 23 species of ape alive today, spread across Central Africa and Southeast Asia. While ancient ape species have been discovered in other parts of the Old World, the history of chimps and humans is firmly rooted in Africa.
But this latest study questions the details of this narrative. It claims that rather than this divergence occurring in the grasslands of East Africa, it may instead have occurred in the Mediterranean. This would mean that the last common ancestor between humans and chimpanzees lived in the Balkans, before splitting and both species then finding its way back into Central and Eastern Africa.
This is likely to be a highly controversial claim, not least because it complicates things somewhat. It has traditionally been thought that humans and chimps went their separate ways as the grasslands in East Africa developed and a new species of pre-human evolved to take advantage of this, finally giving rise to us.
In a second paper published in PLOS ONE, the researchers are saying that these driving forces may well have been the same, but that it really occurred on a newly formed savanna in Eastern Europe around the time that Graecopithecus was roaming.
There is no doubt going to be quite a bit of contention towards these two papers, though it may also raise a fair amount of interesting discussion about what we often think is established fact.