Trachilos footprints: the controversial fossil evidence that challenges what we know about the origins of humanity

A set of footprints discovered by accident on the Greek island of Crete is raising fascinating questions about the origins of humanity, not without controversy.

Trachilos’s footprints were found in 2002 by Polish paleontologist Gerard Gierlinski, and a new study claims they are the oldest known evidence of its kind for human ancestors.

The research was published on October 11 in the journal Scientific Reports by an international team.

Until now, the most widely accepted theory is that hominids originated and evolved in Africa before anywhere else.

Hominids is the term used to describe the group made up of modern humans, extinct human species, and all of our immediate ancestors.

Outside africa

Paleontologists broadly subscribe to the hypothesis that Africa is “The cradle of humanity.”

According to his theory, humanity evolved only on that continent before a “Great migration” to the rest of the world that began less than two million years ago.

Now, the team of researchers led by Swedish paleontologist Per Ahlberg challenges this timeline, claiming that the Trachilos footprints have six million years.

Until now it was considered that Laetoli footprints, discovered in Tanzania in 1976, they were the earliest direct evidence of a human-like foot. Those of Trachilos they would be almost 2.5 million years older.

Discoveries in Africa have been crucial in putting together the family tree of our species.

In addition to footprints, numerous prehuman fossils have been found in Africa in the last 100 years.

The discoveries include the skull of the Sahelanthropus, which is estimated to have lived in Africa seven million years ago. Is he oldest hominid which is currently known.

On Europe, in comparison, there have been very few fossil discoveries similar bone.

Who left their footprints in Crete?

Ahlberg was also part of the team that published the first article on the Trachilos footprints in 2017.

His most recent study, which came to light in October 2021, reviews the age of the tracks and establishes that they are older, passing 5.7 million years old to 6.05 million.

In their first article, Ahlberg and his colleagues concluded that the tracks resembled those of hominids, especially because of the closeness to hallux (big toe) to the other toes, unlike the feet of primates like gorillas and chimpanzees.

“Nonhuman ape tracks look very different; the foot is shaped like a human hand, with the big toe sticking to the side of the sole and sticking out to the sides, “Ahlberg told the BBC.

“Compared to our fellow primates, our big toes are aligned with the long axis of the footThey do not protrude to the side, ”he added.

Some paleontologists greeted the new findings with skepticism.

Critics questioned the methods used to analyze the clues and some even questioned the veracity of the traces.

Matthew Bennett, an expert professor of footprints at Bournemouth University in the UK, was part of the team that studied the tracks in Greece. Even he is cautious in your assessment.

“Son very intriguing fossil footprints, probably left by a bipedal animal, some form of ape, ”Professor Bennett explained to the BBC.

“But if they are from human lineage, that’s another story, “he added.

To understand Bennett’s hesitation, we must remember once again that few fossil bones of a hominin have been found in Europe.

What’s more, the timeline of human evolution is far from a simple matter.

Paleontologists believe that great apes (orangutans, gorillas, chimpanzees, and humans) arose and diversified during a time known as the Miocene, between 23 million and 5 million years ago.

However, there is little consensus on when humans separated from this group.

Scientists have found evidence of non-human great apes roaming Europe, so it is possible that they had left footprints on Crete, explains Robin Crompton, an expert in biological anthropology at the University of Liverpool in the United Kingdom.

“The tracks could certainly be hominid, and that of course is exciting. But there is still a big question mark that can only be solved with more research and discoveries, ”Crompton told the BBC.

In other words, we need to find more bones and footprints in Europe.

How important are the latest discoveries?

Ahlberg says that there is no doubt that our species, the Homo sapiens, evolved in Africa about 300,000 years ago. But his interest goes much further behind this story.

“This (the African origin of the Homo sapiens) is very well documented, ”he said.

“The question here is whether, much further back in time, the entire human lineage originated in Africa..

“Perhaps this was not the case, as our research suggests that early human ancestors may have roamed southern Europe as well as eastern Africa,” he insisted.

Ahlberg says that, before discarding theories, he is working on the possibility that our ancestors I know they would have extended to Europe previously what we currently believe.

“What we are saying is that the roaming of these early hominids could be greater than people usually think.”

In 2017, the same year that the first article on Trachilos was published, German paleontologist Madelaine Bohme from the University of Tubingen also attracted attention.

Bohme announced that the discovery of the “last common ancestor” of humans and chimpanzees had not been found in Africa, but in Europe.

She and a team of researchers claimed the Greek, as he was baptized, he lived in the Balkan region between 7.18 and 7.25 million years ago.

That implied that she was older than him. Sahelanthropus, until now considered the oldest human ancestor to walk upright.

To date, the remains of Greek consist in a jaw and a single tooth. The jaw, in fact, was found in Greece, 250 km from Crete.

“Our research does not question the history of human evolution after five million years, but what happened before then,” argues Bohme.

Skepticism and science

The controversy sparked by the Trachilos footprints also raises questions about how scientists grapple with a peripheral hypothesis.

Although he has reservations about the Trachilos footprints, Robin Crompton also insists that flatly reject that they may belong to hominids, as his colleagues have done, it does not help the study of the origins of mankind at all.

“They must be investigated, not simply discarded. Scientists must keep an open mind“, said.

Madelaine Bohme agrees and notes that there have been seismic shifts in theories about the origins of humanity.

The hypothesis of Africa as the cradle of mankind, for example, was not immediately widely accepted when the remains of a baby known as the Niño Taung that had 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 instead of Africa”He recalled.

“Science without skepticism is not good science. People must be open to arguments. Yes, we need more research and more discoveries, but seeing colleagues simply discarding our findings is something else entirely. “

Per Ahlberg seems to be especially annoyed by the suggestions of his colleagues that the claims made by his team are extraordinary.

“It’s only because people are desperately married to the theory that humanity originated in Africa that our claims look that way,” he believes.

“In this sense, I’m not worried about what the paleontological community will say now. We have presented the evidence and we have defended our case ”.

“Frankly, fighting people’s disbelief is not interesting”He added.

Fingerprint theft

As a footnote, the Trachilos footprints have certainly sparked more than scientific curiosity.

Eight of the footprints were even chiseled out of the rock and stolen a few weeks later their discovery was announced in 2017.

Subsequently, the Greek police arrested a local high school teacher and recovered the fossils.