Question: Why do we have hair?

Sam Tazzyman answered on 24 Jun 2011:

Since our ape ancestors had hair, it’s actually quite interesting to think of why we might have lost our hair, and why we kept some of it. We do have hair cells on nearly all of our body, but the thickest parts of it are on our heads, in our armpits, around our genitals, and for men, on our faces. I understand the hair on our heads because we use lots of energy in our brains, and we lose lots of energy through the tops of our heads, so the hair is to keep some in. I don’t know about the rest, though.