Guns, Germs, and Steel, by Jared Diamond, is one of the most informative books I’ve read in my life. It discusses how the differences in natural resources in different parts of the world influenced how different civilizations developed, or failed to develop. In discussing Africa, and why no major civilization has ever developed there, he mentions the zebra, among a great many other factors. He says that one factor contributing to the lack of a great African civilization is the fact that the Zebra cannot be domesticated, unlike the horse in Europe and other places where they had horses. Who knows? Maybe if they’d had the opportunity to crossbreed it with other breeds, like in the examples above, things might have turned out differently.