Human hair growth pattern compared with animals.

[anni.g]

Why is there such a disparity in the way hair grows on the human head compared to the rest of the body? Apart from our scalps from where hair can grow down to the waist or longer, if left uncut, we are almost bald on the rest of our bodies - even pubic hair and men's chest hair is relatively short. Other animals have longer hair on some parts of their bodies than others, as for example in the case of lions' or horses' manes, but no other animal seems to show the extreme of almost complete hairlessness on most parts of the body accompanied by the ability to grow hair to great and apparently unnecessary length from another part. Why are we so extreme and apparently unique in this respect?

[Isaacr]

One of the theories as to why humans have such a thick concentration of hair on their head is that it gave them an evolutionary advantage when first walking upright in the African savannah. If you imagine an animal upright on two legs, during midday, when the sun is hottest, the top of the head and shoulders are presented to the sun, which is directly overhead. Sunstroke is pretty unpleasant, but prolonged exposure of the brain to the sun can easily and quickly result in overheating and death. So by protecting the head with hair the first bipedal humans protected their brains at the most crucial part of the African day.

[Vasquoy]

You also have to remember that the number of hairs on the human body hasn't really changed - it is just that the hairs have got finer and smaller.

 

I watched a programme on "freaks" and they were talking about "bearded people" and they said that it wasn't an increase in the number of hairs, just a change in the thickness and length