Jared Diamond, an evolutionary biologist and biogeographer who has worked extensively in New Guinea, rejects racially oriented explanations for differential human development. He agrees that the explication for European success is biological, but believes that intelligence had nothing to do with the differential development of societies. Geography had everything to do with it. Differences among environments resulted in dissimilarities among societies. Change its environment and a society would follow a very different evolutionary path. Although human history was not determined in detail by biology, the ultimate causes of the grand sweeps of human history were environmental and geographical. In taking this approach to human history, Diamond hopes to make the discipline more akin to the historical sciences (ecology, paleontology, evolutionary biology) and less a humanities or social science field.For Diamond to demonstrate how environment and geography influence the development of societies, he must first explain how humans obtain food. According to him, human societies can be divided into either hunter-gatherers, who hunt wild animals and/or gather wild plants, or farmer-herders, who domesticate plants and animals and eat the resulting livestock and crops.
The latter ultimately have an advantage over the former. Farming and herding, which Diamond calls food production, result in food surpluses, which in turn lead to larger populations and sedentary, stratified societies with specialized members (such as warriors). These larger and more densely populated societies create technology, invent writing, and serve as hosts for epidemic diseases, the three significant factors in the ability of one society to conquer another. The key factor that determines the relative state of one society versus another, then, is when those societies made the transformation from hunter-gatherers to food producers. Some societies never do, at least not in the time allotted to them by history before their conquest by other societies. Hence, the fate of Native Americans and the aboriginal Australians was sealed when they came into contact with the food producers of Europe. Others made the transformation relatively late or only partially. Thirty-nine of the fifty-six are native to Eurasia (Diamond’s term includes North Africa, which is environmentally much more like the rest of the Mediterranean than sub-Sahara Africa). These grass species include wheat, barley, and rice. Moreover, many of the Eurasian grass species were easier to cultivate. As a result, food production in Eurasia occurred sooner than in other parts of the world. Plants, however, are but part of the food production package. Domesticated animals are equally important.
Again, Eurasia had an enormous advantage. More than half of the 148 candidates for domestication (defined by Diamond as terrestrial herbivorous or omnivorous mammals weighing more than one hundred pounds) are native to Eurasia. More significantly, thirteen of the fourteen species of large mammals domesticated before 1900 are native only to Eurasia. The only exception is the ancestor of the llama. Diamond argues vigorously that these fourteen are the only large mammal species capable of being domesticated, so that the people of Eurasia had what constituted an unfair advantage over the rest of the world. Domesticated animals brought great advantages in the development of a society. The most obvious were food sources, transportation, power sources, and war. The horse, for example, was instrumental in the Spanish conquest of Mesoamerica and South America. However, there was another less obvious advantage for societies which domesticated animals: the “germs” of the book’s subtitle. A number of epidemic human diseases, such as measles, smallpox, flu, and tuberculosis, apparently resulted from the evolution of viruses that affected animals into viruses that attacked humans. Those societies which domesticated animals eventually developed these diseases.
Over the centuries, however, Europeans and Asians developed some resistance to the infections. In contrast, societies lacking domesticated animals were never exposed to these viruses until they were brought by Europeans. Whether in the Americas, the Pacific islands, Australia, or southern Africa, the first meeting between the natives and European germs was devastating to the native population. First contact ultimately resulted in population crashes. Perhaps nine of ten natives died of smallpox, measles, or other infectious diseases. Germs were the great conquerors of the non-Eurasian world. Steel and guns were the tools for completing the job. Only after disease had wrought its power were the absurdly small numbers of Europeans able to overcome empires. If all these advantages weren’t enough, Eurasians had one more benefit not available to the rest of the world. The continent lies generally along an east-west axis, while the major axes of both the Americas and Africa lie north-south. Because areas along the same latitude have identical day lengths and seasonal variations, they tend to have similar environments. Thus, it is easier for crops to diffuse east-west than north-south.
Combine that with the relative lack of topographical or ecological barriers, and the result was the rapid diffusion of food production from the Fertile Crescent west throughout Europe. In contrast, the tropical climates of parts of the Americas or Africa stopped or slowed down the diffusion of domesticated plants and animals. Increasing the difficulty of diffusion were local barriers such as the deserts and dry plains of south-central North America. Thus, in Eurasia there was a trade in plants, animals, and eventually in technology, which was not possible in either the Americas or Africa. Diamond is well aware that his argument leaves him open to the charge of geographical or biological determinism. He counters that there is a significant distinction between determinacy and predictability. Human history is extremely complex and unpredictable. Human inventiveness was essential for the evolution from hunter-gather societies to great food producer empires. Diamond makes the distinction between his grand deterministic explanation and what he calls “cultural idiosyncrasies” and “individual idiosyncrasies.” The former are cultural features, perhaps minor in themselves and arising from ultimately trivial reasons, that predispose a society toward other choices which are more fundamental and significant.
An example of this is the QWERTY layout for typewriter keys, later utilized in computer keyboards. The latter is another way to describe the impact of great men and women upon history. Diamond believes that individual leaders and cultural idiosyncrasies influence the details of the historical process. However, because some environments are more favorable and supportive than others for human inventiveness, human history, in its broadest and most sweeping aspects, is determined. To demonstrate that his reliance upon geography and environment as the ultimate explanation still allows for the human element, he looks at the question of why European societies have dominated the modern world rather than those of East Asia or the Fertile Crescent. Western Europe was among the last areas in Eurasia to domesticate food. Even as late as the fifteenth century, Islamic and Chinese societies were technologically superior. By the late sixteenth or early seventeenth century, however, European societies were ascending. In both cases, human action made the difference, but it was human action dependent upon the environment. In the case of the Fertile Crescent, the answer was environmental destruction over an extended period of time. The region is ecologically fragile, with less rainfall than northern and Western Europe.
Too many people, too many farms, and too many sheep eventually overwhelmed the vegetation. In the case of China, geography made political unification relatively easy compared to Europe. Instead of many states, each in competition with its neighbors, there was only one state. In Europe, there was always one state willing to embrace an innovation in hope of gaining an advantage in the competition. Once such an innovation was proven advantageous, it rapidly spread through other parts of Europe. In contrast, once an innovation was rejected in China, it disappeared. Diamond points to specific decisions, such as the end of the Chinese treasure fleets in the fifteenth century, which resulted in the loss of Chinese superiority. Geography reinforced the tendency towards centralization of authority in China. However, it was a specific human decision, resulting from local political conflict, which resulted in the termination of the treasure fleets. If they had been continued, then it may well have been the Asian rather than the European part of Eurasia which dominated the other continents. How convincing is Diamond? As in any grand synthesis, it is difficult for a reader to evaluate evidence drawn from a variety of fields, many of which are unfamiliar. (The list of further readings is twenty-eight pages long.) He makes a persuasive case for the role of environment in the general evolution of human societies. His examples of adaptations of less advanced societies to food production, once exposed to it, demonstrate that the apparent backwardness was not genetic in origin.
Many readers may find that the chief pleasure they have in the reading and studying of history is in the details, the idiosyncratic aspects of culture and humans. Such readers will likely find themselves unhappy with the prospect of history as a science—complex, but ultimately deterministic.
