When did humans first wear clothes?

This can be determined by when human clothing/body lice diverged genetically from human head lice (human pubic lice appear to have a different origin in lice from apes acquired from using abandoned ape nests to sleep in and diverged much further back).

This is estimated to be roughly 170,000 years ago. See: http://news.discovery.com/human/humans-first-wore-clothing-170000-years-ago.htm