Well, yes, but the black skin gene had to develop at some point, I was just describing it in a very basic manner. Obviously it would be an instantanious 'oh, I have black skin, lets go north'.
(I know that I'm coming into this topic rather late, so I may not have a solid frame of reference in which to place my reply to this. As the previous comment referred to brown bears and polar bears, neither of which black in any way, I must assume the the 'black skin' phrase refers to that of certain racial variations of Man. IF I AM WRONG, YOU MAY NOT WISH TO WASTE YOUR TIME. I would be happy to delete this post of it is pointed out as being off-topic. I simply do not wish to wade through 400 some posts just now.)
According to evolutionary thought, black skin did not develop at some later point in human development, but rather was the primary case. This makes sense if you consider that Africa is home to the vast majority of higher primates - apes, our closest relatives -, with whom we almost certainly (from a Darwinian standpoint, mind you) share a common relative. It stands to reason that we too would have developed in the same geological area, and this is supported by the fossil evidence.
The emergence of Man was recent enough (geologically, at least) that it is safe to assume that the world had roughly the same shape it now holds, or at least close enough for Africa to have been the same equatorial hotspot it is today. This is a bit simplified, but when the sun hits skin, a reaction is caused which ends in the production of Vitamin D. Now, large excesses of VD can cause a rather painful death. This can be avoided, however, by changing the rate at which the skin absorbs the sunlight, and the most expedient way in which to do this would be to alter the skin itself. The route taken by evolution was to select for, from the very beginning, those who were of a darker tone, and thus better equipped to survive in a sun-choked environment. You may know that darker skin is also less susceptible to certain cancers.
In fact, it wasn't until interglacial periods during the pleistocene epoch when man would have been capable of traveling far enough north for dark skin to be a disadvantage. The problem was reversed: There was significantly less sunlight, and they could not absorb what little was available. So it came to be that a series of mutations (always entirely random, and only ever selected for if truly advantageous to survival) brought about the lighter skin tones. So it turns out that everyone who is not black is a mutant. This is rather alleviated by the fact that every human who is not a prosimian (think of the shrew) is also a mutant, which puts everything into perspective.
Also, monkeys are not apes, at least not according to the system by which all living things are catagorically organized (from which we recieve the name Homo sapiens sapiens). Apes are the highest form of primate, and man is included among their ranks. Monkeys are far more primitive in both intelligence and general form. Also, apes are found only in the Old World (Europe, Asia, and Africa) while monkeys are also found in the New World (South America). Note that apes tend not to have prehensile tails, so Fyxe's comment on why we do not have one would hold true.
Edited by Death Adder, 04 July 2006 - 03:33 AM.
