How do we know cave men were hairy?

Interesting article here.

From the article:

The colours of a bird that lived 120 million years ago have been revealed from trace remains of pigments on its fossil, and the same technique may be used to reveal the colours of dinosaurs.

Humans are apes according to scientific classification, we just evolved from one type of ape to another type of ape. If you want to get slightly more technical then we are classified among the great apes along with gorillas, chimpanzees, and orangutans.