In most cases, when you find a fossil — and you don’t always find it yourself, but one of your team finds it — they find something that is very unimpressive. It’s basically a fragment that is sufficiently preserved, that you can say, “Well, this is a fragment of a human ancestor.” It’s a piece of a skull, or it’s a piece of a leg bone, but its anatomy — the anatomical detail — is distinctive from the anatomy of a similar element from another species. So you can say, “It’s not a baboon, it’s not a monkey, it’s not a lion, it’s not an antelope. This is a human ancestor.” But it’s just a scrap. You then look further, and you end up, if you’re lucky, finding other pieces, some of which will fit back onto the original discovery. So you then get a fragment that is a little bigger. In some cases, you are very lucky. You find a fragment, a skull, and in time you pick up — through excavation or a combination of screening and excavation — you pick up enough that you can begin to piece together what the skull looked like.