bookmark_borderA body that requires a brain

Originally uploaded by Ryan Somma

One thing about human evolution that has been puzzling me for years is that there are several areas where the human body seems to be dependent on a highly developed brain:

  • Human head hair (and to some extent, facial hair) just keeps growing, which means it will need to be cut, combed and/or washed. While this is hardly a problem for modern humans, I wonder what an animal with the intelligence of a chimpanzee would do if it developed human head hair.
  • The same applies to human nails. The ones on the hands might be worn down through use, or by biting one’s nails, but the nails on the feet tend to require some attention. Do apes have similar nails, and if so, how do they cut them?
  • Finally, the human buttocks are so big that fæces tends to get stuck, which is why we use toilet paper (in other cultures, water is used instead). Monkeys and apes tend to have smaller buttocks that are less likely to get filthy, but again I’m not certain what they would do if their buttocks evolved to look like their human counterparts.

In short, I can’t see how human head hair, nails and buttocks could have evolved before the human brain was sophisticated enough to invent combs, knives and toilet paper.

Perhaps it’s not really a problem – I could well be that these features turned up very recently.

I have just always assumed (perhaps wrongly) that the modern human brain was more recent that the human body, but perhaps it’s really the way round.