The science of why most marathon winners are from east Africa - Vox
"All six winners in Boston today are originally from the same corner of the world: east Africa. And that's true of almost every major long-distance race, going back for years. So why is that? Why do runners from two or three medium-sized countries, none of which have much money or highly developed infrastructure, manage to outrun virtually the entire world —virtually every time they compete?
This is a question that scientists and journalists have been asking since the 1990s, when the trend began, a few years after African nutrition rates caught up with the rest of the world. But the question has never totally been answered, in part because merely asking it touches on some of the most sensitive issues in modern history: colonialism, slavery, and persistent racial inequality both in Africa and outside of it..."