Professor at the Collège de France, Chaire de Paléontologie humaine, Paris; Member of the Institut International de Paléoprimatologie et Paléontologie Humaine Évolution et Paléoenvironnements (IPHEP), Faculté des Sciences, Université de Poitiers, Fra
Breaking the Wall Around the Secrets of Our Origins. How Early Hominids and Their Paleoenvironments Can Explain Our Species
20 years ago we went to the wall with our geologist hammers, then the police came.
The secret of our origin: the origin is probably between seven and eight million. What is very surprising is that during a large part of our story, we don’t believe that we have a story. The first time we believe that we have a story happened when in Germany we found the first fossil hominid- Neanderthal- not far from near Düsseldorf. Now we know that Neanderthals are living in Europe, in Central Asia. We know a lot about their genome, and we know that Neanderthals are species different from our species- from sapiens. Neanderthal is a sister group, the sister species of sapiens. They became extinct very recently- ca. 27,000 years ago.
Darwin and Wallace predictions: we are celebrating the bicentennial birthday of Darwin. So, Darwin predicted that our closest relatives are chimps, and that probably we shall find ancestor for chimps, and for us, in Africa. Vincent Sarich, Allan Wilson, University of California at Berkley, demonstrated in 1967 that with chimps we share, in term of genetic, a lot- the difference is around one percent. It means that we share a common ancestor between chimps and us.
Chimp and human are two sister groups. In terms of palaeontology, I think we have four milestones: one child, Taung Child, coming from South Africa, 2.5 million; two young ladies coming from Ethiopia: one you know, Lucy: 3.2 million, and also another one, Ardi, just published in Science a few weeks ago, 4.4 million; and a young man, Toumaï, coming from Chad; it means “west of the rift valley”. Toumaï is 7 million years old. You have here Toumaï, Ardi, and Lucy.
Toumaï is coming west of the rift. For the first time we found hominid west of the rift. Going west of the rift is just like breaking the wall.
Now with Toumaï we are writing one of the earliest chapters of our story. We are digging with Mission Paléonthropologique Franco-Tchadienne in Chad. A long time ago, we have a lot of sites, a lot of fossils. We are digging in a nice desert, but a very small place, because Lake Chad Basin is 2.5 million square kilometres. You can imagine: we are looking for teeth of one centimetre. It is quite easy. (Laughter in audience) Digging in Djurab Desert, a lot of fossil- more than you can expect! We already got mammal complete skeletons: next time I shall tell you about a complete hominid skeleton.
So, with all these fossils, we can show that at 7 million years we have in this spot of the Sahara, a mosaic landscape, something like the Okavango Delta in Botswana. We can demonstrate that Toumaï in this Mosaic landscape is living in woodland. Here is the cranium of Toumaï, 7 million years old. Of course, when you spend 7 million years in sediment, your cranium is a little bit crushed. So that it’s why we make deconstruction and reconstruction using CT scans and digitalization for each piece of bone .
You see here. Now you are looking at the earliest human face known at the moment. Toumaï was very happy with this reconstruction.
What happened? First point: before we just know early hominid in South Africa and in East Africa: australopithecine, now the early-late Miocene hominids are known between six and seven million years: one at six in Ethiopia, and another one at six in Kenya, and Toumaï in Chad at seven. With Toumaï, you break the wall of the rift, of the great African rift. Now we know that the early hominid are widespread in Africa. So, we have to look everywhere in this path. It is a big deal.
We are looking in Libya. Look, we are very lucky to work in such desert- nice place, no? But, I can tell you: it can be very hot- very, very hot! But, we have here fossils, as you can see. So, going west, it means that we have to find fossil chimp. It means that we have to look about our last common ancestor. I hope to speak to you about him the next time.
At the moment, in our world, I think that the best conclusion that I can tell you is: all of us, you and me, we share the same ancestor- all of us! We are coming from Africa- all of us- we are sister and brother, brother and sister. Thank you.