I agree with your comment.

> Why would hunter gatherers not wear clothes, when they can offer useful protection against the elements?

I was curious about this and looked it up. Apparently there was some period of time during which humanity did not wear clothes. This has been determined by looking at the DNA of hair lice versus clothes lice and seeing where they diverged: http://news.ufl.edu/archive/2011/01/uf-study-of-lice-dna-sho...