Toumai - The oldest human ancestor

(wind whistling) - [Voiceover] This is my story, and the beginning of yours. Who am I? What is happening to me? (dramatic instrumental music) It's been such a long time, I've forgotten my past. For seven million years I was hidden in the sand. These humans are trying to help me remember, to reconstruct my face, my body. The place I was born. There was a place with trees and water. I see glimpses of the past. What happened? I know my name is Toumai, and I am your new ancestor. This is my story, and the beginning of yours. Seven million years, it's hard to imagine. I come from 230,000 generations before you. I could have disappeared from the face of the Earth forever. The ground swallowed me up, I became a fossil. For nearly seven million years I was forgotten, and I forgot all about my past. And then, they found me. They didn't expect to find me here. For 30 years, the world's scientists believed that mankind originated in the east of Africa. I, Toumai, came from the west of the Great Rift Valley. From the Djurab Desert of Northern Chad. These are the humans who found me. Paleontologists from Chad and from France. They believe I am part of the skull of a hominid. A cranium nearly seven million years old. If it's true, it will turn the previous theories about the origin of man, upside down. This is Professor Michel Brunet. He has long suspected that the theories of the origin of man are incorrect. 20 years ago, he set out to explore west of the African Rift Valley. Michel and his team discovered the first hominid fossil in Central Africa; the jaw of an australopithecine. He is named Abel, and he is 3.5 million years old. (dramatic instrumental music) Then, in 2001, they found me, Toumai. I could be the oldest known ancestor of mankind. - [Voiceover] How can he be so sure I'm a hominid? And what is a hominid? They called me Toumai, which means "hope of life" in the local Guran language. - He's a messenger from the very deep past. - And I picked up the phone and he said, "David, we've got it." - [Voiceover] Some scientists held to the previous theories. They doubted that I was the skull of a hominid. Michel Brunet has set out to prove that I am. First stop, the Synchrotron. An extraordinary machine which generates an X-ray beam 1000 billion times brighter than conventional X-rays. It is like a scanner, and can produce the precise images of me Michel needs. There is a problem, you see. I'm an almost complete skull. Except that my lower jaw is missing. But I've been squashed down on one side, and bits of the ground have stuck to me. The first step in determining what I am is to restore my true shape. And to work out what is really part of me and what isn't. What's Toumai, and what's not Toumai. (tense instrumental music) The engineer points out my canine. my two premolars and the three molars. He seems to find it interesting that each of the two premolars has three root canals. - [Voiceover] So does that mean I'm a bit like both? Second step, the professor asked another group of specialists to make a virtual reconstruction of me. They loaded 500 pictures of me into their computers. From these pictures, they start to build an image in three dimensions, which corrects my distortions. The two scientists each worked separately, and each made two independent reconstructions using different methods. In the end, they created four models. - We are now comparing our two independent reconstructions to see if we converge or differ. - [Voiceover] Now Michel can study the results. The four models are strikingly similar. In particular, they make it possible to determine precisely how far the flat plane at the back of my cranium, what they call the nuchal plane, was inclined backwards. Apparently, hominids and great apes differ in this respect, so this is an important clue. They compare me to the great apes, that's me in the middle. Their analysis supports the idea that I am a hominid. The computer image is turned into a resin cast, using a machine they call a laser stereolithograph. The virtual reconstruction becomes real, solid. It's a strange sensation to see my own face appear, gradually emerging from this time machine. So this is what my proper shape is. The next step in rebuilding my head is a visit to Elizabeth Dane's workshop. She will add muscles and skin to the resin cast of me. Using forensic science techniques to determine how the muscles should go. Only a few specialists in the world know how to do this. And I'm glad to be in Elizabeth's expert hands. It looks like we might be here for some time. I can't wait to see what I really look like. My head seems to be coming along nicely now. Professor Brunet watches over every stage, and checks that each minute detail is scientifically accurate. (soft instrumental music) - [Voiceover] Is that really what I looked like? - [Voiceover] Scientists never seem to agree about anything. So before going any further, Michel wants to test what he's discovered on another expert. We set off to see David Pilbeam, Professor of Anthropology at Harvard University. - [Michel] You remember this one? - [David] Monsieur Toumai. - [Voiceover] Hello Mr. Pilbeam. - [David] He's a little bit crushed, a little bit distorted. Beautiful specimen, beautiful specimen. - [Michel] But you have never seen this one. - [Voiceover] And the professor shows him the 3D model of me in resin. - Ah, this is what Zoe did? - [Michel] Yeah. - [David] May I see it? - [Michel] Yeah. - [David] Fantastic. - [Michel] Yeah, good work. - A good biped, I think. I really expected that an early hominid would look something like an African ape, a chimp or a gorilla. More like a chimp. No, definitely no. - [Michel] No. - Nothing, big surprise, and these still, these enormous brow ridges. Clearly a male, yeah? - [Michel] Yeah yeah. Clearly a male. - [David] If this was a female, I wouldn't want, I would want to meet the male on a dark night. - [Voiceover] Well, of course I'm a male. I could have told them that! - Yeah. - [Michel] And with this. - [David] Yeah? - [Michel] Something completely new. And... Okay. Okay. - It's beautiful! He's very handsome. - When we are looking at him now, we are looking at the earliest face of humanity. I like his face. - [David] Yeah, yeah. The more you look at it the more you can easily imagine that he's alive. - [Voiceover] The two professors sit themselves down in a room with a lot of different skulls. Great apes, chimpanzees and gorillas, and hominids. They talk a long time, but this is the gist of it. My upper canine is small in size. It's worn down at the point, in the same way your human canines tend to do. My face is shorter and flatter than those of the great apes, and my brow ridge, which Mr. PIlbeam has so admired, is very pronounced. Lastly, there is the backward tilt of my nuchal plane. - They don't look like African ape. We must be quite close to the split of chimps and humans. - [Michel] Sure. (heartbeat thumping) - [Voiceover] Having got this far, I'm embarrassed to ask, but what is a hominid, when you get down to it? What makes a hominid different from an ape? Apparently hominids have small canines, and walk upright on two feet. - When most animals walk, all primates, they hold their head so that the eyes are looking forward. In addition, the foramen magnum, this hole, is pretty much always perpendicular to the orientation of the neck. It can only move about 10 degrees. So if you put Toumai's head on a chimpanzee's body, its eyes would always be pointing downwards, it would have to crane its neck to look forward. But of course if you put Tuomai on a human's neck, because of the orientation of the foramen magnum, its eyes look forward. It has to be a biped. - [Voiceover] If you draw a line across the opening where my spine meets my head, and another up to my eye sockets, the angle formed is larger than a right angle, as in you humans. Michel and David conclude there can no longer be any doubt, I really am a hominid. But I don't understand how they can be sure I'm so old. Time for another expedition. (adventurous music) Michel sets off to look for more fossils. For the 11th year in a row, his caravan returns to the Djurab Desert of Northern Chad. For me, it's a chance to revisit the place where I was born. The Jeeps stop at Salal, the last village outpost on the edge of the vast, empty Djurab. It's our last chance to stock up on supplies of water and fuel. For these humans, these supplies are vital. Otherwise, they won't be able to survive the desert environment. They say it's too hostile. (speaking in Arabic) And we're off. (camels grunting) And we've stopped. I suppose Michel doesn't have the same impatience as I do. It takes us three whole days to reach our destination. As soon as they wake in the morning, Michel examines me once more, along with the Chadian paleontologists, Taiso and Endosa. They have been important members of the expedition team for 10 years, and the fossils found here will be delivered into their care. (soft, bright music) They're going to start looking near where they found me. If they find more fossils, these will give them more clues about my past, about my age. Most importantly, they say they're hoping to find the remains of other hominids, other Toumais. - [Voiceover] So there's not much chance of them finding any other Toumais then. In fact, I'm amazed they can find anything at all, with the sand and the wind whirling constantly around us. - [Voiceover] I couldn't share in Michel's optimism. They can hardly see their hands in front of their faces, let alone find something small in the sand. But then I heard them say that the wind can actually help, by exposing fossils which had been completely hidden in previous years. - [Voiceover] I notice that they only find the odd little fragment, so it really is rare and exceptional to find a fossil like me. - [Voiceover] So there are other Toumais, but where? Apparently it wasn't a desert when I lived here. This is what Philippe Duranget has found out. Philippe is a geologist, and he discovered traces of plant life, and is working out how the climate evolved long ago. He has concluded that this area was in fact, once a lakeside, and probably resembled a place called the Okavango. The Okavango river has this peculiar characteristic. It never flows into a sea or an ocean. In Botswana its waters spread out over the sandy plains of the Kalahari Desert to form a vast delta. It is made up of a succession of shallow lakes, water courses lined with forest, and wooded savannah. Michel and I traveled to the Okavango, to find out whether it does resemble the place I used to live. By studying the right type of habitat, and the creatures in it, Michel can judge more clearly how I lived, what I ate, what threats there were to my survival. Guides who know the area well are going to help us find what we're looking for. Many scientists believe that the early hominids started to walk upright because their habitat changed. Instead of living in forests, they were adapting to the open savannah. Michel thinks that the story is more complicated, and that I lived in a wooded environment. But can we find an environment like that? One which would give me protection, and provide me with the right types of food? This is certainly a pleasant place, though I'm not sure all the locals are friendly. (hippo grunting) When we were in Chad, I saw the others find enormous bones, and I think they might have come from the same animals. Michel says some of the bones belong to ancestors of the creatures we see in the Okavango today. (dramatic orchestral music) - [Voiceover] After taking them out of the ground, the scientists protect the best animal fossils from my era in plaster. They are very important to determining my age. - [Voiceover] Seven million years. That means I'm the earliest hominid known so far. That's better, back to civilization. This is Professor Jaeger, and he's borrowed me for a while to have a look at my teeth. - [Voiceover] I was able to eat tougher types of food. Professor Jaeger measures the exact carbon composition released by my tooth enamel. From this he can deduce whether, for example, I ate grass or leaves. He discovered that I ate all sorts of things. Fruits, nuts, new leaves, young shoots, termites, roots, tubers, food which came from a wooded environment. But having a varied diet is easier said than done. It is, you might say, a tough nut to crack. - [Man] So what do you think, Michel? - [Michel] Yeah it's nice, it's a good, ripe fruit. - I think if Toumai arrived here, maybe there was loads on the floor, I think he'd have a feast. - [Michel] And I'm sure you have a nut. - [Man] From one to another. - The problem here is that you have just this kind of fruit. - Yeah, so there's no variety. And so when the marula are gone, what does he do then? - Cross this! (laughter) Too dangerous, too dangerous. - [Voiceover] Too dangerous, what if it is? It's all very well for them to laugh, but if we didn't have enough food, we had to venture out in the open. But that meant taking a terrible risk. Out there, there's no shelter, and there may be predators about. Now we know what Toumai ate, but what ate Toumai? Back in the Okavango, Michel is still trying to identify some prime hominid habitat. A place where I, and those like me, could have thrived, and raised healthy offspring. For hours, he travels up and down the meandering waterways of the Okavango. Then, suddenly, one particular area of vegetation attracts his attention. - [Man] A lot of food in there. - You see? - [Man] Lunch, yeah. It's a little dry. - [Voiceover] I heard them say these water lily root stalks are so nutritious, they are still eaten today, by people who live in this area. The scientists believe we may have lived in groups, similar to those of chimpanzees. Groups of at least six members, both females and males, headed by a dominant male. Yes, this does look like a lovely place. Now I can really let my imagination run wild. Michel never leaves me in peace for a moment. We're back on the road again, and sometimes I'm forced to travel in the most terrible conditions. But then, I am a scientific phenomenon, and lots of people want to see me. Until Michel's team found Abel, and then me, all the great fossil discoveries took place in the east of Africa. There, they found fossils which are just a little younger than me. At least, only a million years or so younger. Many of these important hominid fossils are held here, at the National Museum of Ethiopia. I understand that Michel wants to introduce me to one of them. Ardipithecus Kadabba. He's 5.8 million years old, the most ancient hominid fossil of Ethiopia. That's Professor Tim White, of the University of California. A world expert in human evolution. The two scientists are joined by Doctor Yohannes Haile-Selassie, who discovered Ardipithecus Kadabba. Professor White compares the teeth of Ardipithecus with those of my species, and notes that we both have a very similar jaw structure. He even goes so far as to say that I could be the ancestor of Ardipithecus. This could be a vital clue, implying that hominids may have gradually migrated from West to East Africa. But Michel seems to have some reservations. - For me, it's too early to answer. I have not enough. - You have not enough. - We have not enough, it's too early. But at this time, you, Yohannes and me, we can be sure, that we are the same evolutive grade. And it's very important because it's a new one. - [Voiceover] The scientists have a new surprise for me. They're going to introduce me to another important figure. - [Tim] You see, Herto. 155,000 to 160,000 years old, the earliest *** sapiens, the direct ancestor of modern humans. So we have, in terms of our understanding of human evolution now, we have an understanding at the beginning and at the end of this story. - That's a wonderful moment, to have on the same table, the earliest sapiens, and the earliest hominid. - We have not only these end points, but we have literally thousands of fossils in the middle, like this one from the Lucy species. The jaw that is incontrovertibly not an ape, and also, not a human. - [Michel] No. - It is something in-between. Toumai is obviously not a human being. A human ancestor, yes. - [Michel] Yeah. - Because we know the features of its face, particularly its teeth, its cranium. It looks like it's on our evolutionary line, but right near the base of the line that would ultimately lead to things like Herto in Ethiopia. - [Voiceover] While in Addis Ababa, Michel pays a visit to someone important, Lucy. A small female Australopithecus discovered 30 years ago. For many years, she was the oldest-known ancestor of mankind. Now, all that has changed. For Michel, Lucy is an important symbol, because she is situated halfway between you and me on the evolutionary scale. Since she is 3.2 million years old, she is in fact, slightly closer to you than she is to me. I am a hominid. My official name, Sahelanthropus Tchadensis, alias, Toumai. I'm nearly seven million years old, a new species of pre-human being. The closest known to the split between chimpanzees and humans. I am mankind's new ancestor. This is the end of my story, and the beginning of yours. (upbeat instrumental music)