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We Are Older Than We Thought |
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Michel Brunet has found a skull that’s between 6 and 7 million years old in the African nation of Chad that he’s named Toumaï. The skull is the oldest human fossil ever found, and comes from the time when humans and chimpanzees were just becoming separate species. Since this is the first time a skull this old has been discovered, "There must have been a group of apes knocking around between 5 and 8 million years ago for which there's a very poor fossil record," says anthropologist Bernard Wood of George Washington University.  Most fossils of ancient humans are less than three million years old. After Toumaï, the next-oldest is 6-million-years old, and we only have a few teeth and bone scraps from him, so this find means we were around much earlier than we thought. "When I first saw the skull I thought, 'Gee, it's a chimp'," says anthropologist Daniel Lieberman of Harvard. A closer look "blew my socks off", he says. Toumaï may be primitive, but he’s definitely a hominid, not an ape. He has smaller canines and thicker tooth enamel than apes. The point at the back of skull where neck muscles attach suggests that he walked upright. Many of Toumaï's advanced features are actually missing from later fossils, but reappear in still later species that are classified as early man. The lesson in all this, Wood believes, is that we can’t judge evolution solely by appearances. Hominid and ape species probably mixed with each other when the two species first diverged, with the same traits evolving independently as they went their separate ways. Lieberman thinks Toumaï was a male because "It's got a massive brow ridge, the size of a large male gorilla, and yet it's just a little hominid." He says, "I'm willing to bet some money that this is a hominid." Tim White of the University of California agrees, but Wood says, "My guess is that it's neither a chimp nor a human ancestor - it's a creature that was living at the same time." We’ll never solve this mystery unless we find more fossils from the same period. The problem is, the forests that chimps and our earliest ancestors liked to live in are not places where fossils are easily formed. For example, chimps are certainly here today, but scientists have never located their fossil record. But whether or not Toumaï was one of us, he was at least an early human precursor, which sets our history back even further. Click here to go back to the Science Vs Religion menu | |||||
