Oldest human or just another ape? Row erupts on 7 million year old fossil

It’s a dispute that has taken a long time to come to a boil. Seven million years after an ape-like creature – since dubbed Toumai – passed through the landscape of modern Chad, its mode of travel has sparked a row among fossil experts. Some claim it was the oldest member of the human line. Others that he was just an old monkey.

The row, lit by a paper in Naturelast week led to scientists slamming opponents while others accused rivals of building theories on “less than five minutes of observation”.

The heart of the dispute is simple. Could Toumaï – which means “hope of life” in Chad’s local Daza language – walk on two feet, an ability that suggests he may well be the oldest member of the human family? Scientists who unearthed the fossil remains believe this to be the case.

Others vehemently disagree. They say Toumai – a member of an extinct species known as Sahelanthropus tchadensis – was not bipedal but moved on all fours like a chimpanzee. Claims of ancient human ancestry are false, they claim, accusing opponents of sifting through the data.

The dispute is resentful even for paleontology, a field known for its bitter controversies over the interpretation of ancient skulls and bones. In this case, the dispute began with the discovery in 2001 in the Djurab desert of a deformed skull and other bones by French and Chadian paleontologists. They concluded that the shape of the skull meant it must belong to a creature that walked upright.

“It’s a lot of emotion to have the beginning of the human line in your hands”, said at the time a member of the team, Michel Brunet from the University of Poitiers. This discovery made Brunet a scientific star in France, especially in Poitiers, where a street bears his name.

Professor Michel Brunet, from the University of Poitiers, holding the skull of Toumaï at the University of N'Djamena in Chad.
Professor Michel Brunet, from the University of Poitiers, holding the skull of Toumaï at the University of N’Djamena in Chad. Photography: Patrick Robert/Corbis/Getty Images

However, the interpretation was based solely on examination of the skull, the critics said. The other bones had been put aside until their examination in 2004 by Aude Bergeret-Medina, also from the University of Poitiers. She recognized a leg bone and concluded it was from a primate that walked on all fours – not two. Above all, she was supported by her supervisor, Roberto Macchiarelli.

It took Macchiarelli and Bergeret more than a decade for their findings to be published. Attempts to present their findings to the Paris Anthropological Society have been blocked, they say, while Macchiarelli has been accused of scientific misconduct by his opponents.

A report of their work eventually concluded that it indicated that Toumai was a four-legged creature and was unlikely to be a founder of the human line. “The evidence supporting bipedalism is very, very poor,” says Macchiarelli.

Last month, the skull and bone researchers published their answer in Nature and said bone examination indicated bipedalism, suggesting he had a closer relationship to humanity than apes. On Twitter, one of the team members, Franck Guy, accused Macchiarelli and his colleagues of basing their conclusions on 5 minutes of observation and a few photos. “Our article is a five-year study,” he added.

Other scientists, including Professor Bernard Wood of George Washington University, have dismissed Guy’s claims while supporting the argument that Toumai’s bones indicate he looked like a chimpanzee.

Professor Chris Stringer of the Natural History Museum in London was more cautious. “It’s a shame that these disputes are undermining what are truly important discoveries,” he told the Observer. “Given the peculiar and largely unknown circumstances of the find – the bones appeared to have been collected by someone and placed on desert sand – we don’t even know if the bones of the skull, legs and arms belong together in as a unique individual.

“I would say the jury is still out on whether Toumai was perfectly suited for walking on two legs.”

Oldest human or just another ape? Row erupts on 7 million year old fossil

Leave a Comment

Your email address will not be published.