Humans first wore clothes about 72,000 years ago, according to an analysis of head and body lice that has provided the first estimate of when fashion was born.
By employing a cunning genetic approach that takes advantage of the way clothing influenced the evolution of the head louse Pediculus humanus - Professor Mark Stoneking and his team at the Max Planck Institute for Evolutionary Anthropology in Leipzig have been able to explore this dark era.
The earliest piece of linen from Egypt dates to 5,000 BC, yet, because clothing does not fossilise, it has not been possible until now to say when the birth of the first togs a key stone-age innovation took place.
The story of lice and men is reported today in the journal Current Biology by Prof Stoneking and his colleagues Ralf Kittler and Manfred Kayser, who analysed variations in the genetic make-up of parasites.
While head lice live and feed on the scalp, the more recently evolved body lice feed on the body but live and reproduce on clothing. When humans began to make frequent use of clothing, head lice moved into clothing and evolved as body lice, said Prof Stoneking.
Thus, the team reasoned, by working out when the evolution took place, they would get an indirect measure of when our ancestors first took to wearing furs, skins and other ancient apparel.
Analysis of various kinds of head and body lice revealed the modern genetic variation in the parasites and, assuming genes mutate at a given rate, the 72,000-year estimate came up.