Evolution

Owen Lovejoy

Ardipithecus was found in the mid 90s but it was in very poor condition. It comes from about about 40 miles away from where lucy was found, but it's 4.4 million [years old] so it's more than a million years older than Lucy. It took about three or four years just to clean the specimen because the bones are so soft. .. We've been working on it for the past ten years the exciting thing about it is that it's more complete than Lucy and it has more informative parts than Lucy had. Lucy had no hands or feet but Ardipithecus has both, so it tells us a great deal about how humans evolved in terms of locomotion. But in terms of how they manipulated the world and most importantly how we differ from the way chimpanzees and gorillas evolved.

The most striking thing is is that everybody in the world up to now has thought that we evolved something that was generally chimpanzee like it turns out that chimpanzees have evolved from something that's more human-like. So the evolution that we see is pretty much the reverse of what we thought. The ancestor was completely different than anyone would have predicted and there's no way you could have predicted by looking at either a modern human or looking at a modern chimpanzee. You had to have a fossil record [for the correct conclusion]. That's why our Pittacus is so exciting. What Lucy did was create a huge question, and that question is is why did we evolve this weird form of locomotion which doesn't have a lot of advantages. You're pretty slow, pretty awkward. You're not as agile as a chimpanzee or gorilla, you can't climb trees very much anymore, so you're not as safe. You can't nest in trees and yet the brain is no bigger so what the heck is going on?

The other thing is that the male in her species has very small canines which is something unlike any higher primate. All male higher primates have large what are called sectoral canines they project well above the other teeth and when they when the mouth closes, they rub against one another, and hone one another to keep them as sharp weapons. When you look at Lucy's species and you look at the canines they're the same height as the other teeth they don't hone and so the males could not have been using them as weapons. So the argument was is that the canine had reduced in size in order to make room and space and developmental energy and for the production of the large molars? Well those large molars are [suitable for] living on open savannas where the food is very coarse a lot of his underground tubers things that wear away the dentition very rapidly.

Ardipithecus gives us a whole new vision a million years before Lucy. Ardipithecus's had really primitive molars, they weren't large, she was an omnivore not a Savannah dweller. She lived in trees and in woodland and yet the male canines are small and she's becoming bipedal so we now have the key factor, that bipedality and reduction of the canine evolved in concert with one another. The male was became more successful if he was less aggressive and more food supplying bipedality became an important carrying mechanism. You didn't need a lot of social cooperation because you were still arboreal and as a consequence this was a major adaptive breakthrough. Then once you were a pretty good biped and the females were all pretty cooperative with one another, and so are the males, then the species started to expand. Then we became a what is called a weed species which we've been ever since.

Darwin would be ecstatic. He didn't have any fossils, the only fossils he had [was some] Neanderthals, his theory was pretty good [sure], I mean Darwin argued that we the canine reduced because we took up tools and that the brain got big because we began to use tools, and that was his algorithm for human evolution. It's completely wrong, but it's only wrong because of what we know today. It's a perfectly good theory. It's just the ugly facts that we've discovered, but you know, that's the way science proceeds, its disproving what you used to think was correct.