ScienceHair and EvolutionTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoScience05/29/2016May 29, 2016Paleobiologist Christine Hertler says the loss of thick hair made extended periods of exertion possible in our ancestors. Effort generates heat, and sweating dissipates it. But for that to work, the skin has to be free of too much hair.https://p.dw.com/p/1IvRrAdvertisement