The prehistoric footprints that call into question ideas about the origin of humanity

A series of footprints discovered by accident on the Greek island of Crete has given rise to several fascinating questions, some quite controversial, about the origin of humanity.

Known as the Trachilos footprints, the vestiges were found in 1976 by the Polish paleontologist Gerard Gierlinski. Only recently a surprising study found that the discovery two decades ago represents the oldest known evidence of human ancestors of this type.

The research of an international team, published in 11 October in Scientific Reports, challenges the currently most accepted theory that hominids (a term used to describe a group that includes modern humans, other extinct species, and all our immediate ancestors) arose and evolved in Africa before any other place on the planet. Africa is “the cradle of humanity”.

According to this explanation, humanity evolved only on that continent before a “great migration” to the rest of the world, which began less than 2 million years ago .

But the team of researchers led by Swedish paleontologist Per Ahlberg is calling this timeline into question: they claim that Trach’s footprints ilos are 6 million years old.

This would make the footprints millions of years older than those generally considered to be the first direct evidence of a human-like foot used for walking: the Laetoli footprints, discovered in Tanzania in 1976.

The discoveries on the African continent were crucial to building our “family tree”.

) In addition to the footprint, several pre-human fossils have been found in Africa in recent years 100 including the skull of Sahelanthropus, which is estimated to have lived in Africa 7 million years ago, it is the oldest hominid known today.

Europe, in comparison, has had very few discoveries of fossils of similar bones. So, who left the footprints in Crete?

Ahlberg was part of the team that in 2017 published the first scientific article on the footprints of Trachilos the study of October 2021 was a geological analysis of the footprints that pointed to an older date for them, revising their estimated age from 5.7 million years to 6,05 million.

In the original article, Ahlberg and colleagues concluded that the traces resembled hominid footprints, especially in the way the hlux (toe) seemed to be close to the other fingerprints, unlike the feet of primates such as gorillas and chimpanzees.

“The footprints of non-human primates look very different; p is shaped like a human hand , with the finger stuck in the side of the sole and protruding laterally”, explained the Swedish researcher BBC. “Compared to our fellow primates, our toes are aligned with the long axis of the foot, they don’t stick out to one side.”

Doubts and Skepticism

As is often the case with scientific works that challenge widely accepted theories in paleontology, the study of the Trachilos footprints was received with skepticism by some paleontologists.

Those who dispute the results question the methods used to analyze the footprints. Some of the experts, by the way, even raise the hypothesis that the footprints are not real.

The world’s leading expert on footprints, Professor Matthew Bennett, from Bournemouth University, in the United Kingdom, was part of the team studying the clues in Greece, but even he is cautious in his assessment of dates.

“These are very intriguing fossil footprints, probably left by a biped animal, some form of ape,” explained Bennett BBC . “If the footprints are of human lineage, that’s another story.”

To understand Bennett’s hesitation, we need to remind one more time of the absence of fossil bones from hominids in Europe instead.

Furthermore, the human evolution timeline is far from being a simple matter.

Paleontologists believe that the great apes (orangutans, gorillas, chimpanzees and humans) have emerged and diversified during a time known as the Miocene, from almost 18 million to 5 million years ago.

But just now consensus on when humans “separated” from them.

Scientists have found evidence of non-human great apes roaming Europe, so it is possible that they may be responsible for the footprints in Crete, explains Robin Crompton, professor and expert in biological anthropology from the University of Liverpool, UK.

“The footprints could certainly be homininians, and that’s certainly exciting. But there’s still one big point that it’s just bad. such research and discoveries can answer” the question, said Crompton BBC.

In other words, finding more bones and footprints in Europe is accurate.

How important are Trachilos footprints?

Ahlberg, a Swedish researcher who did not work on footprints in Crete, says there is no doubt that our species, Homo sapiens

, evolved in Africa about 250 a thousand years ago. His interest is long before that.

“This (the African origin of Homo sapiens) is very well documented,” he says. “The question here has been for much longer, whether the entire human lineage originated in Africa.”

“Perhaps not, as our research suggests that human ancestors may have wandered into southern Europe first, as well as in East Africa,” adds Ahlberg.

Rather than simply refute the hypothesis Leaving Africa, Ahlberg says he is working with the possibility that our ancestors may have spread to Europe earlier of what we currently believe.

“All we are saying is that the reach of these first homininians may be greater than people are used to thinking.”

In 2017, the same year that the first article on Trachilos’ footprints was published, German paleontologist and professor Madelaine Bohme, from the University of Tbingen, made headlines on her own. She announced that the discovery of the “last common ancestor” of humans and chimpanzees has not been found in Africa, but in Europe.

Bohme and a team of researchers said the creature, named Graecopithecus, lived in the region of Blcs there are 7,11 and 7,18 millions of years, therefore older than Sahelanthropus, currently considered the oldest human ancestor to walk upright.

So far, the remains of Graecopithecus consist of a single tooth and a jaw, the latter found in Greece, 250 km from Crete.

“Our investigations do not challenge the history of human evolution after 5 million years ago, but what happened before that,” argues Bohme.

Skepticism and science

The controversy provoked by Trachilos’ footprints has also sparked debate about how scientists deal with an off-the-curve hypothesis.

Despite his hesitations about Trachilos’ footprints, Robin Crompton of the University and from Liverpool, adamant that rejection as hominid tracks by other experts does nothing to help the study of the origins of humanity. Scientists need to keep an open mind,” he said.

Madelaine Bohme agrees, noting that there have been seismic-dimension shifts in theories about the origins of humanity.

The hypothesis from Africa, for example, did not immediately become accepted by most experts when the remains of a child known as the Taung Child, who lived 2.8 million years ago, were found in South Africa in 1924. “There were times in history when it was believed that humanity could have originated in different parts of the world, not Africa.”

For her , “science without skepticism is not good science, but people need to be open to discussions. And yes, we need more investigation and more discoveries, but colleagues are simply discarding our findings for something totally different” see.

Per Ahlberg, linked to the study of the footprints of Crete, seems to be particularly irritated by criticism of “It’s only because people are so desperately attached to the idea of ​​the Out of Africa theory that our claims are seen in that way,” he says. We present the evidence and present the defense of our discovery.”

For him, “fighting people’s unbelief is frankly uninteresting.”

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