The evidence used to answer this question comes from a few main sources, including bones bearing evidence of skinning, sewing needles and awls, and lice. This type of lice evolved to grasp human head hair wouldn't survive among human pubic hair, for example. But before our ancestors lost their fur, those lice probably roamed all over their bodies. By looking at when head lice separated from clothing lice, scientists have estimated that those two types diverged about 3 million years