LONDON, ENGLAND—Mel Greaves of The Institute of Cancer Research in the United Kingdom thinks that human ancestors had pale skin when they lost their body hair some two to three million years ago. The lack of hair was “almost certainly to facilitate heat loss by sweating in physically very active hunters, especially in the more open, dry and hot Savannah” of East Africa, Greaves told Discovery News. It had been theorized that melanin, the pigment that gives skin color, evolved as an adaptation to limit damage to the skin from sun exposure. Greaves studied albinos living in Africa, who lack any pigment in their skin, hair, and eyes, and found that they are indeed highly susceptible to skin cancer. “We assume that all hominin migrants from Africa over the past 100,000 years would have been dark skinned. What happened to those migrant populations’ skin color later depended upon geography and UVR (ultraviolet radiation) exposures,” he added.