Oldest Homo Sapiens Fossils Are Found in Morocco, Rewriting History of Humanity
June 09, 2017 07:48 AM EDT
The oldest known Homo sapiens fossils, dated 300,000 years old, have been found by anthropologists in a site called Jebel Irhoud in Morocco.
The findings were published in the journal Nature on Wednesday, and are evidence that humankind did not evolve solely in south or east Africa as previously thought, but rather throughout the entire African continent.
"We did not evolve from a single 'cradle of humankind' somewhere in East Africa," said Philipp Gunz, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Germany, according to the New York Times.
The oldest Homo sapiens fossils previously were found at two sites in Ethiopia: one called Omo-Kibish, where scores of fragments dated to 195,000 years ago were found, and another at Herto where a skull roughly 160,000 years old was found. The new fossils in Morocco have been determined to be 300,000 years old, making them the oldest fossils of our species.
A paleoanthropologist named Jean-Jacques Hublin started studying fossils and other artifacts at Jebel Irhoud in the 1980s after miners dug up pieces of a skull and flint blades. Dr. Hublin noticed that the jawbone and teeth of the skull looked similar to modern humans, even though the shape of the skull was primitive.
The discovery of these skulls seemed to contradict the previously held theory that Homo sapiens evolved in East Africa and then spread out over the continent.
To date the fossils, Dr. Hublin studied flint blades found in the same sedimentary layer as the skulls, which were most likely used as spears. Many of the blades showed signs of having been burned. The paleoanthropologists have hypothesized that the people at Jebel Irhoud lit fires to cook food, and heated discarded blades that were buried in the ground below the fire.
With this in mind, Dr. Hublin and his colleagues used a method called thermoluminescence to determine how much time has passed since the blades were burned, and estimated that they were roughly 300,000 years old. The skulls, found in the same rock layer, must be the same age.
Remarkably, the skulls found at Jebel Irhoud resemble modern humans in many ways, such as the flat and wide shape of their faces, which paleoanthropologists think may have had to do with the advent of speech. But in many ways the brain cases of these Homo sapiens were still reminiscent of early hominins, such as in the lack of a distinctively round shape that modern human brains have now. Despite some primitive features, the hominins do belong to the Homo sapiens species and not to other hominins such as Neanderthals.
Dr. Hublin and colleagues traced the source of the flint used in the blades to a site about 20 miles south of Jebel Irhoud, which indicates that early Homo sapiens knew how to search out and use resources over long distances. This suggests that flint blades found in other parts of Africa may have been made by early Homo sapiens. If that is true, then our species may have been evolving as a network of groups spread out across the continent.
There is still much research to be done, because the presence of other fossils from the same era may mean that the blades were used by other hominins. As Hublin said, reported by CNN, "We would support the notion that around 300,000 years ago, very early forms of Homo sapiens were already dispersed all over Africa."
The fossils start to fill in a previously blank spot in the history of the human species, from between 200,000 and 300,000 years ago, and can be seen as an intriguing slice of evolutionary history.