My 9-year-old daughter has stumped me with a question. She asked me why the shape of eyelids differ in different races. She used the example of Japanese versus Caucasian people. Any thoughts?
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鈥� I was surprised that neither of the answers published (15 February) mention sexual selection, Darwin鈥檚 other great insight into evolution.
A memorable passage in Jared Diamond鈥檚 Guns, Germs and Steel quotes a man from the New Guinea highlands on the great beauty of the local women, with their tight curly black hair, their eyes very close together, and their noses spread right across the face. He contrasts them to ugly western women, with their hair like dead grass, their eyes wide apart like a pig鈥檚, and their axe-blade noses.
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These are all features for which it is hard to assign any evolutionary advantages, but which are easily accounted for in terms of sexual selection. It may be that the epicanthic fold confers no evolutionary advantage, but is considered more beautiful in some cultures, and so predominates.
鈥淭he epicanthic fold may confer no advantage, but is considered more beautiful in some cultures鈥�
Stephen Thomson, Ashfield, New South Wales, Australia