What is \"human\"? (Evolution)

by dhw, Saturday, October 17, 2009, 17:46 (5325 days ago)

David (under "Evolution"): The expectation was that the common ancestor was more ape-like, following Darwin's suppositions. Ardi is more 'advanced' than was expected. The common ancestor may be further back than 6 million years with this finding about Ardi.-I don't really know where the 6 million years came from in the first place. I find all such dates pretty unconvincing, but if they have to be put back a million or ten million years, that still doesn't invalidate (or, of course, confirm)Darwin's "ape-like" theory. However, the more I think about it, the more nebulous this whole concept of ape/human becomes. Hence the new thread.-What constitutes "human"? David writes: "the brain increase in size was one of the last things to happen in the evolutionary development of humans." For me, it's the brain and everything that's associated with it that goes to make up our humanity: the almost infinitely more refined consciousness, language, inventiveness etc. Changes to the pelvis or the limbs or the feet, hands or teeth don't seem to me to make a major distinction between human and ape. In terms of molecular biology, we can apparently be classified alongside chimps as homininae, whereas orangutans (ponginae) are in a different subfamily even though they're also apes. So in that context an orangutan is more distinct from chimps than we are!-If we go back to Ardi, she may be more advanced than was expected, but advanced in what way? Does primitive bipedalism really make her more human? If we suppose, say, that changes in the vegetation led to certain anthropoids taking to the ground and walking upright ... or alternatively to certain anthropoids moving from the ground to the trees ... no matter what developments took place in the anatomy, without the enlarged brain wouldn't we still see them as more ape than human? -One theory (I can't remember where I read it) is that bipedalism freed the hands, the hands began to use tools, and the brain grew larger as a result of the extra mental activities involved. This suggests that the thought came before the enlargement, and raises the questions: where do thoughts come from and how can they enlarge the brain? The alternative would be how does an enlarged brain create thought, and if that is the way it happened, why did the brain get bigger in the first place? Of course it did get bigger, and we're here to prove it, but I'm not sure if we need a palaeoanthropologist, a neuroscientist, or a philosopher to sort out how it happened, and to tell us what "human" actually means.