Mr. Atahualpa? Meet Mr. Smallpox

Jared Diamond's "Guns, Germs and Steel: The Fates of Human Societies" (W.W. Norton & Co. 1999) explains everything.

Well, anyway, it explains why Europeans arriving in America in the late 15th century were the ones with steel swords, horses and plagues, all of which allowed them to easily conquer huge, populous American empires. And why Europe, rather than China or Africa, wound up colonizing pretty much the whole world from the 15th through 19th centuries.

Short version: Eurasia, because of its size, geography and luck of the draw, had more domesticable species of animals and plants than the other continents, and easier ways to spread them between population centers. Building villages and growing food is the first step in a feedback loop that produces large, dense populations and advanced technology. Scattered populations without food production do not have the specialists to develop technology (see Australia), and often don't even adopt it when introduced, if there's no pressure from competing societies to do so.

Domesticated herd animals (Eurasia had the Big Five of pigs, sheep, goats, cattle, horses) provided germs that mutated into epidemic human "crowd diseases," like the ones that killed off 95 percent of Native Americans after Columbus arrived. The Native Americans had only dogs, alpacas (only in the Andes), turkeys (Mexico) and guinea pigs (Andes again).

Europe, rather than the Mideast or China, wound up colonizing the rest of the world because a) the Mideast's arid climate made it too fragile for intensive farming over thousands of years and b) China's early political coalition allowed conservative, despotic rulers to choke off innovation for political reasons hundreds of years ago. Europe, with lots of rain and splintered, competitive states, had the food to feed non-peasant specialists like inventors and soldiers, and the wars to ensure that its societies adopted new tech and organization or were destroyed. So they got the world-conquering tech-and-government package first, and that head start made all the difference.

The stuff on germs also explains why Europeans never populated the tropics the way they did the temperate zones of North America, Argentina/Chile, South Africa and Australia. They couldn't handle the tropical diseases, while the locals had developed resistance over thousands of years.

Nice to have a non-racial explanation for the relative wealth and power of different societies, because aside from the repugnance of racial theories, they have lots of holes in them and don't stand up to scrutiny.

I don't know if I go along with Diamond completely in his proposal of a "science" of human history. Bogus scientification has been the death of literary criticism, and I don't want to see the rest of the humanities go further down that path. But I agree that stepping back from the short-term causation of history does allow a better grasp of the big trends. Jared's previous book, The Third Chimpanzee: the evolution and future of the human animal, studied human prehistory at the point where humans diverged widely from apes in tool use and hunting ability (about 50,000 years ago; Diamond theorized that the development of the voice box and language made the difference). As he gets closer to modern history, studying shorter periods of time, I don't think the strengths he brings from evolutionary biology and physiology will be as useful in explaining the behavior of as complex a system as a world of 6 billion tech-using humans.