Homo ergaster/erectus, of which we have many fossil specimens, is a very persuasive halfway link, no longer missing, between Homo sapiens today and Homo habilis two million years ago, which is in turn a beautiful link back to Australopithecus three million years ago, which, as we saw, could pretty well be described as an upright-walking chimpanzee. How many links do you need, before you concede that they are no longer ‘missing’?
