large-seeded cereals (Table 8.1). One extension would be to assemble corresponding numbers for large-seeded legumes (pulses), such as beans, peas, and vetches. In addition, I mentioned factors disqualifying big mammalian candidates for domestication, but I did not tabulate how many candidates are disqualified by each factor on each continent. It would be interesting to do so, especially for Africa, where a higher percentage of candidates is disqualified than in Eurasia: which disqualifying factors are most important in Africa, and what has selected for their high frequency in African mammals? Quantitative data should also be assembled to test my preliminary calculations suggesting differing rates of diffusion along the major axes of Eurasia, the Americas, and Africa. A second extension will be to smaller geographic scales and shorter time scales than those of this book. For instance, the following obvious question has probably occurred to readers already: why, within Eurasia, were European societies, rather than those of the Fertile Crescent or China or India, the ones that colonized America and Australia, took the lead in technology, and became politically and economically dominant in the modern world? A historian who had lived at any time between 8500 b.c. and a.d. 1450, and who had tried then to predict future historical trajectories, would surely have labeled Europe's eventual dominance as the least likely outcome, because Europe was the most backward of those three Old World regions for most of those 10,000 years. From 8500 b.c. until the rise of Greece and then Italy after 500 b.c., almost all major innovations in western Eurasia—animal domestication, plant domestication, writing, metallurgy, wheels, states, and so on—arose in or near the Fertile Crescent. Until the proliferation of water mills after about a.d. 900, Europe west or north of the Alps contributed nothing of significance to Old World technology or civilization; it was instead a recipient of developments from the eastern Mediterranean, Fertile Crescent, and China. Even from a.d. 1000 to 1450 the flow of science and technology was predominantly into 410• EPILOGUE Europe from the Islamic societies stretching from India to North Africa, rather than vice versa. During those same centuries China led the world in technology, having launched itself on food production nearly as early as the Fertile Crescent did. VlS$T' Why, then, did the Fertile Crescent and China eventually lose their enormous leads of thousands of years to late-starting Europe? One can, of course, point to proximate factors behind Europe's rise: its development of a merchant class, capitalism, and patent protection for inventions, its failure to develop absolute despots and crushing taxation, and its Greco-Judeo-Christian tradition of critical empirical inquiry. Still, for all such proximate causes one must raise the question of ultimate cause: why did these proximate factors themselves arise in Europe, rather than in China or the Fertile Crescent? For the Fertile Crescent, the answer is clear. Once it had lost the head start that it had enjoyed thanks to its locally available concentration of domesticable wild plants and animals, the Fertile Crescent possessed no further compelling geographic advantages. The disappearance of that head start can be traced in detail, as the westward shift in powerful empires. After the rise of Fertile Crescent states in the fourth millennium b.c., the center of power initially remained in the Fertile Crescent, rotating between empires such as those of Babylon, the Hittites, Assyria, and Persia. With the Greek conquest of all advanced societies from Greece east to India under Alexander the Great in the late fourth century b.c., power finally made its first shift irrevocably westward. It shifted farther west with Rome's conquest of Greece in the second century b.c., and after the fall of the Roman Empire it eventually moved again, to western and northern Europe. The major factor behind these shifts becomes obvious as soon as one compares the modern Fertile Crescent with ancient descriptions of it. Today, the expressions 'Fertile Crescent' and 'world leader in food production' are absurd. Large areas of the former Fertile Crescent are now desert, semidesert, steppe, or heavily eroded or salinized terrain unsuited for agriculture. Today's ephemeral wealth of some of the region's nations, based on the single nonrenewable resource of oil, conceals the region's long- standing fundamental poverty and difficulty in feeding itself. In ancient times, however, much of the Fertile Crescent and eastern Mediterranean region, including Greece, was covered with forest. The region's transformation from fertile woodland to eroded scrub or desert THEFUTURE OF HUMAN HISTORY AS A SCIENCE • 4 I I has been elucidated by paleobotanists and archaeologists. Its woodlands were cleared for agriculture, or cut to obtain construction timber, or burned as firewood or for manufacturing plaster. Because of low rainfall and hence low primary productivity (proportional to rainfall), regrowth of vegetation could not keep pace with its destruction, especially in the presence of overgrazing by abundant goats. With the tree and grass cover removed, erosion proceeded and valleys silted up, while irrigation agriculture in the low-rainfall environment led to salt accumulation. These processes, which began in the Neolithic era, continued into modern times. For instance, the last forests near the ancient Nabataean capital of Petra, in modern Jordan, were felled by the Ottoman Turks during construction of the Hejaz railroad just before World War I. Thus, Fertile Crescent and eastern Mediterranean societies had the misfortune to arise in an ecologically fragile environment. They committed ecological suicide by destroying their own resource base. Power shifted westward as each eastern Mediterranean society in turn undermined itself, beginning with the oldest societies, those in the east (the Fertile Crescent). Northern and western Europe has been spared this fate, not because its inhabitants have been wiser but because they have had the good luck to live in a more robust environment with higher rainfall, in which vegetation regrows quickly. Much of northern and western Europe is still able to support productive intensive agriculture today, 7,000 years after the arrival of food production. In effect, Europe received its crops, livestock, technology, and writing systems from the Fertile Crescent, which then gradually eliminated itself as a major center of power and innovation. That is how the Fertile Crescent lost its huge early lead over Europe. Why did China also lose its lead? Its falling behind is initially surprising, because China enjoyed undoubted advantages: a rise of food production nearly as early as in the Fertile Crescent; ecological diversity from North to South China and from the coast to the high mountains of the Tibetan plateau, giving rise to a diverse set of crops, animals, and technology; a large and productive expanse, nourishing the largest regional human population in the world; and an environment less dry or ecologically fragile than the Fertile Crescent's, allowing China still to support productive intensive agriculture after nearly 10,000 years, though its environmental problems are increasing today and are more serious than western Europe's. These advantages and head start enabled medieval China to lead the world in technology. The long list of its major technological firsts includes 4 12 •EPILOGUE cast iron, the compass, gunpowder, paper, printing, and many others mentioned earlier. It also led the world in political power, navigation, and control of the seas. In the early 15th century it sent treasure fleets, each consisting of hundreds of ships up to 400 feet long and with total crews of up to 28,000, across the Indian Ocean as far as the east coast of Africa, decades before Columbus's three puny ships crossed the narrow Atlantic Ocean to the Americas' east coast. Why didn't Chinese ships proceed around Africa's southern cape westward and colonize Europe, before Vasco da Gama's own three puny ships rounded the Cape of Good Hope eastward and launched Europe's colonization of East Asia? Why didn't Chinese ships cross the Pacific to colonize the Americas' west coast? Why, in brief, did China lose its technological lead to the formerly so backward Europe? The end of China's treasure fleets gives us a clue. Seven of those fleets sailed from China between a.d. 1405 and 1433. They were then suspended as a result of a typical aberration of local politics that could happen anywhere in the world: a power struggle between two factions at the Chinese court (the eunuchs and their opponents). The former faction had been identified with sending and captaining the fleets. Hence when the latter faction gained the upper hand in a power struggle, it stopped sending fleets, eventually dismantled the shipyards, and forbade oceangoing shipping. The episode is reminiscent of the legislation that strangled development of public electric lighting in London in the 1880s, the isolationism of the
