Early man shed his hair gradually to cope with the heat of active, foraging lifestyle, a new study has suggested.
Previously scientists have speculated that man first ‘stood up’ as a means of keeping cooler.
But a new computer model suggested that it was the other way round – standing up would have made us hotter and we lost our hair as a result.
It seems early humans stood up, and then lost our hair as we realised how hot it was running around on two feet.
By modelling temperature for what humans would consider ‘an active lifestyle’ against levels of hair from ape-like to human, the researchers, led by Graeme Ruxton of the University of Glasgow, suggested that early man would only at first have been able to run around in early mornings and evenings.
It would have become essential for us to shed our hair, in order that we could gather food for more and more of the day.
Otherwise, our thick coats would have been so hot that we simply couldn’t cope.
As we lost our fur we would have become active for more and more of the day.
“Our model suggests that only when hair loss and sweating ability reach near-modern human levels could hominins have been active in the heat of the day in hot, open environments,” the Daily Mail quoted the researchers as saying.
The study has been published in the journal Proceedings of the National Academy of Sciences.