For the past three weeks, I’ve been in Uganda doing research on my next book, Lost White Tribe: Explorers, Scientists, and a Theory of Race that Changed Africa (New York: Oxford University Press, 2015). The book begins in 1876 in East Africa, where the journalist and explorer Henry Morton Stanley encountered four Africans whose light complexion and European features “aroused curiosity to the highest pitch.” They came from the slopes of Gambaragara, a snow-capped mountain west of Lake Victoria.