In 1997’s Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond set out to answer an age-old riddle: How come it was the Europeans who sailed the ocean blue to conquer and slaughter their New World counterparts, rather than the other way around? Was it because the white man had more on the ball, cranially speaking (as the Europeans themselves took for granted)? Nah, says Diamond, who uses his background in molecular physiology, evolutionary biology, and biogeography to craft a theory of human development that’s as elegant as it is understandable. The folks from Eurasia just plain lucked out, according to the Pulitzer Prize-winning author, by coming to ground in a place rich not only in large-seeded grass species but in big domesticable mammals. (The Europeans got sheep, goats, pigs, cattle, and horses; a few lucky New Worlders got…the llama.) From this munificence sprang forth all manner of gifts: The ready availability of large domestic animals led to improvements in farming, which in turn freed up people to fight wars of conquest, invent new weapons, and develop cricket. Proximity to said creatures also had the inadvertent side effect of breeding nastier germs, which worked even better than sophisticated weaponry when it came to devastating distant adversaries. As Diamond says: “History followed different courses for different peoples because of differences among peoples’ environments, not because of biological differences among peoples themselves.” In other words, the destinies of human cultures lay not in racist theories of human genetics but in terms any real-estate agent could understand—location, location, location. Diamond revisits his book at 7 p.m. Thursday, Feb. 6, at Politics and Prose, 5015 Connecticut Ave. NW. Free. (202) 364-1919. (Michael Little)