A new fossil discovery on the island of Crete in the Mediterranean is threatening to rewrite the history books when it comes to human evolution.
Footprints found in the Trachilos region of western Crete bear all the markings of a human or hominin foot, and here’s the surprise: they are dated by stratigraphy at approximately 5.7 million years ago, suggesting that not only did early humans live in both Europe and Africa but that Europe may have been their true place of origin.
The well-known story of human history as it’s currently told identifies Africa as our evolutionary ground zero, a theory adopted in the mid-19th century and solidified by findings in the mid-20th century with the discovery of fossils of Australopithecus in South and East Africa. About eight million years ago, early proto-humans called hominins first started to break off from their common ancestor lineage with chimpanzees, with the earliest evidence of a fully bipedal Australopithecus now identified at about 3.6 million years ago from human-like footprints left in volcanic ash in Laetoli, Tanzania.
But the new findings challenge that picture, say the authors of a study published in the Proceedings of the Geologists’ Association. The international team comprised of researchers from Europe and the United States who analyzed the fossil footprints and together concluded that they’re hominin in origin, owing to a number of characteristics. Unique among land animals, human feet involve a long sole and claw-less, forward-pointing toes which are entaxonic, meaning that they have one toe (or finger) larger than the others (the thumb and great toe).
“The tracks indicate that the trackmaker lacked claws, and was bipedal, plantigrade, pentadactyl and strongly entaxonic,” say the study’s authors. “Morphometric analysis shows the footprints to have outlines that are distinct from modern non-hominin primates and resemble those of hominins.”
Importantly, the oldest known hominin from Africa, Ardipithecus ramidus from Ethiopia, existed 4.4 million years ago and possessed a more ape-like foot. Researchers put Ardipithecus as a direct ancestor of later hominins (and eventually humans), implying that the distinctively human foot had not yet evolved at 4.4 million years ago.
At 5.7 million years, the new find would push back the date when hominins got their human feet by a good couple million years, an accomplishment in itself, but it would also put into question the Africa-first theory, a fact of which the study’s authors are well aware.
“This discovery challenges the established narrative of early human evolution head-on and is likely to generate a lot of debate,” says Per Erik Ahlberg of the Department of Organismal Biology at Uppsala University in Uppsala, Sweden, in a press release. “Whether the human origins research community will accept fossil footprints as conclusive evidence of the presence of hominins in the Miocene of Crete remains to be seen,” says Per Ahlberg.
At present, the evolutionary picture has homo sapiens appearing on the scene by 160,000 years ago, with their migration out of Africa and occurring around 50,000 BCE. Homo sapiens are thought to have first travelled to India and Asia, followed by Europe sometime around 40,000 years ago. Migration to Australia is dated at 40,000 years ago, while travel to North America — across the Beringia land bridge, down through Alaska, Canada and the rest of the Americas — is said to have occurred less than 20,000 years ago.
Another recent find, fossil specimens of Graecopithecus freybergi dated at 7.24 million years old and discovered in Greece and Bulgaria, is also contributing to the Eurocentric evolutionary rewrite. In a study co-authored by University of Toronto paleoanthropologist Bavid Begun, researchers analyzed a lower jaw fragment and an upper premolar from Graecopithecus, arguing that they belong to a pre-human.
“These research findings call into question one of the most dogmatic assertions in paleoanthropology since Charles Darwin, which is that the human lineage originated in Africa,” says Begun.