A new study has found that mankind's ancestors may have started walking on two legs simply because it allowed them to carry more food away in their hands, boosting their chance of survival.

William McGrew, professor of Evolutionary Primatology at the University of Cambridge, told the Today programme's Justin Webb that they tested the "carrying hypothesis" which postulated that animals stood up because they had free hands to carry objects.

He said that "when competition was heightened over a valued resource in an unpredictable nature, it brought out bipedality", or walking on two legs.

Get in touch with Today via email , Twitter or Facebook or text us on 84844.