I am now confused about whether this is all about epicanthic folds, or smaller noses.
QUOTE (TheSecret @ Aug 14 2009, 08:34 PM)
I had thought the fold was mainly found of the people in only a particular reigion, and surely it then makes sense to say those people tend to have it as a result of it being naturally selected...somewhat similar to people in africa having darker skin....
I'm probably missing out a lot, and I don't understand it completely, hence asking the question. Of course, the question does not just to have to apply to the fold. It can apply to skin color as well..., if Australians remained on our island for tens of thousands of years, would we eventually adapt to have a darker skin color? Ignoring the fact that mxied races and such would probably negate that ever happening....
Say we take it as a given that the various ancestors of the peoples of eastern Asia, and their descendants, have the fold.
I am surprised to see it not appear elsewhere, in parallel.
Also, if there was some selective pressure for it in place, what advantage does it actually give? I mean, is a person without that fold going to die in noticeably larger numbers before their, i don't know, 15th birthday?
I am also a little confused as to how the sun on snow causes one group of peoples to develop epicanthic folds, but the sun elsewhere causes people to get darker skin. I mean, I can understand darker skin because it'll lower the incidence of cancer, or maybe infection from bad sunburn, but I'm slightly struggling to see even the reasoning behind that one.
Assuming the sun does provide some selective pressure on skin colour, then I don't really see Australians - even if you cut off all immigration now and into the future - getting magically darker skin. Because I don't think that selective pressure is there anymore.