Guns, Germs, and Steel: The Fates of Human Societies.

Guns, Germs, and Steel: The Fates of Human Societies, by Jared Diamond (Norton, 448 pp., $27.50)

Mr. Sailer ([e-mail]) is a writer in Chicago.

AN early version of this book's subtitle illustrates its ambitiousness: A Short History of Everybody for the Last 13,000 Years. Jared Diamond's goal is to explain why Eurasians conquered Africans, Australians, and Americans instead of the other way around, even though conventional social scientists shy away from such a fundamental question out of fear of what they might find. Since random accidents of personality and culture appear too trivial to account for the lopsided outcomes when continents clash (e.g., a few hundred Conquistadors demolished the grandest empires of the New World), this leaves only two possible underlying causes: either the winners had better homelands, or they had better bodies and brains. Deeming genetic explanations "racist" and "loathsome," Diamond sets out to reaffirm the equality of humanity by showing the inequality of the continents. To him, the three most important engines of history are location, location, and location.

Few are more broadly qualified than he to write history in terms of geography and sociobiology. A molecular physiologist at UCLA, Diamond is also an evolutionary biologist. His 33 years of birdwatching in the tropics, especially in New Guinea, home to one thousand of Earth's six thousand languages, put him in touch with a remarkable variety of human beings. Diamond wrote little for popular audiences before his dazzling 1992 book, The Third Chimpanzee: The Evolution and Future of the Human Animal. In contrast to that kaleidoscopic page-turner, Guns, Germs, and Steel hammers away at a single thesis. Nonetheless, it rewards the effort.

Diamond argues that the broadest aspects of the modern world --e.g., the domination of North America by whites -- were largely determined by the con- tinents' dissimilar natural resources of domesticable plants and animals. Regions offering an abundance of these could support the transition from hunter-gatherer to farmer-herder, allowing higher population densities. And those communities that could free up the most manpower from farming to specialize in technology and war could conquer their neighbors. A few areas, especially the Middle East, were home to many easily domesticated foods: both grains such as wheat and large mammals such as cows and sheep. Other parts of Eurasia such as Europe were close enough to the Fertile Crescent for early diffusion of these crops and livestock.

In contrast, much of the Earth -- including seemingly congenial landscapes like California -- lacks native plants that would be more profitable to cultivate than to gather. What valuable vegetation the New World did possess, like Mexico's corn, was slow to migrate north and south along the Americas' main axis because crops' growing seasons are sensitive to latitude.

Also, the New World was badly lacking in large domesticable mammals. Excluding boutique operations, humans today raise just 14 species of mammals weighing over one hundred pounds. Of these, only the llama is native to the Americas. Of course, 13,000 years ago the New World teemed with potentially useful beasts like horses and camels. Then the American Indians arrived and, Diamond says, ate them. This rapacity made their Aztec and Inca descendants both militarily impotent and dreadfully susceptible to the Conquistadors' diseases. The Spaniards, in contrast, were heirs not just to Eurasia's foods and tech- nologies, but also to immunities to its germs. Since the worst contagious dis- eases afflicting human beings descended from farm animals' diseases (e.g., smallpox from cowpox), native Americans had few diseases of their own with which to fight back.

Mr. Diamond is not content, however, merely to write the history of the last 13,000 years. He also claims that his evidence is politically momentous because it shows that no ethnic group is inferior to any other: each exploited its local food resources as fully as possible. For example, after the Australian Outback explorers Burke and Wills exhausted their Eurasian-derived supplies, three times they had to throw themselves on the mercy and expertise of the local Stone Age hunter-gatherers. These Aborigines, the least tech- nically advanced of all peoples, may not have domesticated a single Australian plant in forty thousand years, but in two hundred years Down Under scientific whites have domesticated merely the macadamia nut. Farming pays in Australia only when using imports.

But, are indigenous peoples merely not inferior? In truth, on their own turf many ethnic groups appear to be somewhat genetically superior to outsiders. Diamond makes environmental differences seem so compelling that it's hard to believe that human beings would not become somewhat adapted to their homelands through natural selection. And in fact, Diamond himself briefly cites several examples of genetic differences affecting the course of history. Despite military superiority, Europeans repeatedly failed to settle equatorial West Africa, in part because they lacked the malaria resistance conferred on many natives by the sickle-cell gene. Similarly, biological disadvantages stopped whites from overrunning the Andes. Does this make Diamond a loathsome racist? No, but it does imply that a scientific-minded observer like Diamond should not dogmatically denounce genetic explanations, since he is liable to get tarred with his own brush.

The undeniability of human biodiversity does not prove that we are also some- what diverse mentally, but it's hard to imagine why the brain would differ radically from the rest of the body. Consider the fable of the grasshopper and the ant. The ant's personality traits -- foresight and caution -- fitted him to survive predictably harsh winters. Yet, the grasshopper's strengths -- improvisation and spontaneity -- might furnish Darwinian superiority in the unpredictably dangerous tropics.

Like many, Diamond appears to confuse the concepts of genetic superiorities (plural) and genetic supremacy (singular). The former are circumstan- ce-specific. For example, a slim, heat-shedding Somalian-style body is inferior to a stocky, heat-conserving Eskimo physique in Nome, but it's super- ior in Mogadishu. In contrast, genetic supremacy is the dangerous fantasy that one group is best at everything. Before the European explosion began in the fifteenth century, it seemed apparent that no race could be supreme. Even the arrogant Chinese were periodically overrun by less cultured barbarians. The recent European supremacy in the arts of both war and peace was partly an optical illusion masking the usual tradeoffs in talents within Europe (e.g., Italian admirals were as inept as English cooks). Still, the rise and reign of Europe remains the biggest event in world history. And yet the era when Europeans could plausibly claim supremacy over all other races has been dead for at least the sixty years since Hitler, of all people, allied with Japan.

The historian who trumpets the political relevance of his work must consider both the past and the future, which Diamond fails to do. Surprisingly, ethnic biodiversity is becoming more important in numerous ways. Until recently, one's location and social position at birth closely constrained one's fate. But, as equality of opportunity grows, the globalized marketplace increasingly exploits all advantages in talent, including those with genetic roots. Pro sports offer a foretaste of the future: many are resegregating themselves, as ethnic groups increasingly specialize in those games they're naturally best at. In summary, Diamond may prove a better guide to the last 13,000 years than to the next 13.