FRANCE: Searching for our ancestors' ancestors

Professor Michel Brunet has temporarily left the deserts of Libya for the lecture halls of Paris. The scientist who discovered Toumaï, humankind's oldest known ancestor, is the new professor of human palaentology at the prestigious Collège de France. Last month, Brunet expressed satisfaction that by re-establishing the chair, the college had asserted its opposition to Creationism, the theory that rejects evolution and claims that living creatures were created in their present form by a god.

"The vote of the professors of the Collège de France embraces the naturalistic tradition of the college and, at the same time, it is a very strong signal regarding ways of thinking which are turning again to outdated ideas," he said.

Brunet referred to Turkish Muslim creationist, Harun Yahya, who last year targeted France's secular education system by distributing to universities and lycées thousands of copies of The Atlas of Creation. In more than 700 lavishly illustrated pages, the book claimed that living species had never changed and purported to prove that animals, including humans, had not evolved since their 'creation'.

Having spent more than 45 years as a researcher, Brunet felt able to conclude: "Evolution is not a theory, but a fact which has been scientifically demonstrated."

Brunet, 68, is an authoritative man with a trim white beard and a wry sense of humour. He explained when we met a few years ago that his choice of career was linked completely to his childhood: he gained a lasting passion for nature and life outdoors after spending his first seven years living on his grandparents' farm in the wilds of the Vienne department in west-central France.

"I can't stay a long time in a big building. I was interested in biology and animals. I thought of doing medicine but it would have meant being closed in a hospital," he said.

In addition to his new chair at the college, Brunet is professor of human palaeontology at the University of Poitiers, where he is also a member of the International Institute of Palaeoprimatology, Evolution and Palaeoenvironments, and heads the national centre for scientific research laboratory of Geobiology, Biochronology and Human Palaeontology.

In the mid-1960s, Brunet followed his first doctorate in palaeontology from the Sorbonne with another in natural sciences from Poitiers University. During his long career he has worked in numerous countries – including Afghanistan, Cameroon, Easter Island, Iraq, Kazakhstan, Nigeria, Romania, South Africa, Spain, Togo, the United States and Vietnam, as well as France.

But he made his greatest discoveries – so far – in Chad. In 1995 at Koro Toro, a site in the Bahr el-Ghazal region in the north of that country, his team unearthed "Abel", Australopithecus bahrelghazali, a 3.5 million year old hominid. Abel was the first proto-human found west of the Rift Valley that cuts down through the middle of Eastern Africa.

Previously, all early hominid traces had been located in East or South Africa, giving rise to the 'East Side Story' theory that humans originated in East Africa which was formulated (and later withdrawn) by Yves Coppens, Brunet's predecessor at the Collège de France where he was professor of palaeoanthropology and prehistory from 1983 until 2005.

Then in 2001, in the vast Djurab desert of northern Chad, Brunet's team found the fossilised skull of Toumaï, Sahelanthropus tchadensi, with fragments from several other individuals. The sediments in which they were found indicated they were about seven million years old. But controversy flared the following year when Brunet had to face claims from colleagues that Toumaï was not after all mankind's earliest ancestor to date, but more likely to be a female gorilla.

The scientific journal Nature had published a paper by Brunet identifying the skull as from "the earliest known hominid". A subsequent article signed by Milford H. Wolpoff of Michigan University, Brigitte Senut of France's national Natural History Museum, Martin Pickford of the Collège de France and John Hawks of Wisconsin University rebutted Brunet's paper with claims that Toumaï displayed features "that link the specimen with chimpanzees, gorillas or both, to the exclusion of hominids". In short, they believed that Sahelanthropus was "an ape".

But reconstruction of the skull and tests on the cranial, occipital and dental features, together with new state-of-the-art dating techniques, have confirmed that Toumaï, whose name means 'Hope of Life' in the local Goran language, was a hominid who almost certainly walked on two legs and lived between 6.9 and 7.2 million years ago.

After arriving in Chad in 1994, Brunet set up the Franco-Chad Palaeoanthropological Mission (MPFT), a scientific collaboration between the universities of Poitiers and N'Djamena, and the Centre National d'Apui à la Recherche based in the Chad capital. The team of some 50 scientists from 10 countries focuses its main research on origins and history of the first hominids and their environment. Brunet deliberately included Chadians in the team, and N'Djamena University subsequently set up its own palaeontology department.

Brunet's discoveries have forced a major rethink about human origins, evolution and environment. His findings reveal that hominids became established in Africa much earlier than previously thought, seven or eight million years ago, and over a much larger area, including Central and North, as well as Eastern and Southern, Africa.

At that time, the immense region covering what is today Chad, Libya and Egypt was fertile and inhabited by abundant animal life. The biped Toumaï probably lived by a lake in wooded country, not savanna. Brunet believes that Toumaï's ancestors came from the north, and he has recently moved his research operations to Libya and Egypt.

Talking to journalists last month, Brunet pointed out that 2009 will be the 200th anniversary of the birth of Charles Darwin, who developed the theory of evolution. Abel and Toumaï confirmed Darwin's predictions, said Brunet, who with his new appointment intends to "thwart the return to outdated concepts cunningly dressed up as science".

* Brunet's inaugural Collège de France lecture took place at the end of March and the series Ancient hominids – A new history in the light of recent discoveries, will continue until 11 June. For French speakers, lectures at the college, given by eminent academics, are open to everybody free of charge and often accessible online (University World News, 16 December 2007, "Ancient college embraces teaching by podcast")