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The recent paper on Australopithecus sediba once again, brought up the issue of our own evolution. The evidence we have now is extensive and consistent with Darwin's original hypotheses. These are that we have an African origin and that we are on the same evolutionary branch that led to chimpanzees, gorillas and orangutans.

The main tweak has been that we now accept that chimps didn't branch off with gorillas. Rather chimps and humans stayed on the same branch until a split about 5-7m years ago. If we ever get over our need to feel special in the animal world, then we might accept that we're nothing more than a third chimp species (chimps and bonobos being the others).

So, what's some easy ways to tell that we are an ape species?

Well, first of all, look at your hands. Turn your fingers so that they're pointing towards you. You'll see that your fingers are actually a bit flattened, and you've got finger-nails. Now look at your thumb. You'll see it's opposable and that it's not elongated relative to the fingers. You won't find these characters on carnivores like cats or dogs. Nor on rodents like rats, nor lagomorphs like rabbits. These are traits that are limited to primates and apes.

Second, feel around your skull. Your eye sockets are large and forward looking. Then feel around to the bone that is just behind and to the side of your eyes. That's the post-orbital bone. You should be able to feel it arch a bit, but more importantly, it's closed. That's an ape trait.

Now try feeling the shape of your face. You'll notice that your snout- or rostrum- is pretty flat. That distinguishes monkeys from apes. That flat face puts you in the same family as gorillas, chimps and orangutans. If you feel behind your skull, you'll realise it's rounded and compared to monkeys, it's large. That rounded and enlarged brain-case again, makes you an ape.

If we move onto the finer detail of the skull, we have the jaw. Some primates have an unfused mid-line joint. If you've ever seen an x-ray or model of the human jaw, you'll notice the mid-line joint is completely fused. You can't see it. Guess what- that's the same as the gorilla, chimpanzee and orangutan. The frontal bones of your skull have the same thing. In some primate species these frontal bones preserve a joint. In ape species, these joints have fused completely. And the ape species that have this fusion are humans, chimps, gorillas and orangutans.

So, it's quite easy to see your ape ancestry just by looking at the skull and hands. These are all inheritable traits. It was these sorts of physical traits that led Darwin to deduce our ape-ancestry. What Darwin didn't have was the fossil, molecular and DNA evidence we've since accumulated. And that, will come next…