The first hominin species, a line that eventually leads to humans, may have emerged in Europe 7.2 million years ago and not Africa—the most widely accepted starting point for our ancestors.
An international team of scientists has presented two studies that suggest the divergence point between chimpanzees and humans took place in the Eastern Mediterranean rather than East Africa. Their findings, published in PLOS ONE, are based on two fossils of the species Graecopithecus freybergi, which were discovered in Greece and Bulgaria and have now been dated to between 7.2 and 7.1 million years ago.
Previously, scientists had thought hominins and chimps split between seven and five million years ago, with the first in the hominin line emerging in Africa. But these fossils, scientists say, tell a different story about the onset of human evolution.
Both fossils—a lower jaw and an upper premolar—were examined using state-of-the-art computer tomography, allowing the scientists to look at their internal structures.
Their findings showed the teeth are fused in a way that is characteristic of early humans, including Ardipithecus and Australopithecus, the latter of which the famous Lucy fossil belongs to. The jawbone also had dental root features that appear to belong to a pre-human rather than to an ancient chimp.
This raises the possibility that the fossils represent the oldest hominin ever discovered and that the “major splits in the hominid family occurred outside Africa,” they wrote.
Researchers say environmental changes caused the divergence and used geological analysis to reconstruct the conditions from the Sahara to the Mediterranean during this time. They showed that the desert would have spread far into Southern Europe, creating a barrier between Africa and the locations where Graecopithecus was found.
The study has been met with skepticism because the vast majority of fossil evidence appears to suggest our ancestors emerged in Africa and migrated outwards.
James Cole, Senior Lecturer in Archaeology at the University of Brighton, U.K., tells Newsweek that while the authors are cautious in saying Graecopithecus is potentially the oldest known hominin, their conclusions are still bold: “What they are definitely suggesting is that rather than the divergence point that eventually leads to us—the hominin route—being in Africa, they are strongly suggesting, in both papers, that it is the eastern Mediterranean landscape where that is happening. Which is remarkable.
“It’s certainly not impossible that this is the case. The rate we are finding out about our hominin ancestors in terms of their evolutionary story over the last five years has been absolutely phenomenal. What it probably shows us if anything is that we don’t know an awful lot.”
Cole says that the studies show that there was a connected landmass between Africa and Europe and that the desert between them created a barrier, dividing populations and causing a new species to emerge.
But the fossilised hominim is not necessarily our earliest ancestor and may have separated from some other early species that would eventually go on to become Ardipithecus.
“ If we just try to look at it with hominin dispersals in context, there have certainly been primates and hominin species moving in and out of Africa and we tend to see the drawings of the arrows moving in one direction, but there’s no reason why they can’t be bidirectional,” he says.
“The strength of the study is showing we’ve been very East African focused for the origin point, and that that focus perhaps needs to be broadened a bit more so than we’ve been willing to do in the past. That’s not to say East Africa or the continent isn’t the origin point, but I think it’s clearly demonstrated that there is a lot going on around elsewhere in the Middle East and Europe.
“For me personally, I think Africa is still a strong contender for the split between chimpanzees, bonobos and whatever ends up with us,ancient hominins, but they are certainly putting forward a case in these two papers that is well worth archaeologists, paleoanthropologists, experts in the field, looking again at the record and thinking of if the African story does still stack up.”
In an email interview with Newsweek , study author Madelaine Böhme says they do not doubt the presence of early hominins in Africa, “but the oldest potential hominin has been found in Greece and Bulgaria. That is the fact we present.”
“We not only provide the advanced hominin-like features of Graeocopithecus and a very exact age, we importantly provide a totally new mechanism explaining the split of chimps and humans — we are calling it 'North Side Story'.” She says the barrier the desert would have created would have separated populations for at least 500 to 700,000 years.
Böhme also says it is too easy to consider the specimens as just anomalies within the fossil record: “I dismiss such views,” she says, adding the next task will be to find more evidence to back up their findings: “We will try to find new materials of Graecopithecus. The chances are now quite good.”