Guns, Germs And Steel Part 15

All this suggests that descendants of Austronesian invaders and of original New Guineans have been trading, intermarrying, and acquiring each other's genes and languages for several thousand years on the North New Guinea coast and its islands. That long contact transferred Austronesian languages more effectively than Austronesian genes, with the result that most Bismarck and Solomon islanders now speak Austronesian languages, even though their appearance and most of their genes are still Papuan. But neither the genes nor the languages of the Austronesians penetrated New Guinea's interior. The outcome of their invasion of New Guinea was thus very different from the outcome of their invasion of Borneo, Celebes, and other big Indonesian islands, where their steamroller eliminated almost all traces of the previous inhabitants' genes and languages. To understand what happened in New Guinea, let us now turn to the evidence from archaeology.

AROUND 1600 1600 B.C. B.C., almost simultaneously with their appearance on Halmahera, the familiar archaeological hallmarks of the Austronesian expansion-pigs, chickens, dogs, red-slipped pottery, and adzes of ground stone and of giant clamsh.e.l.ls-appear in the New Guinea region. But two features distinguish the Austronesians' arrival there from their earlier arrival in the Philippines and Indonesia.

The first feature consists of pottery designs, which are aesthetic features of no economic significance but which do let archaeologists immediately recognize an early Austronesian site. Whereas most early Austronesian pottery in the Philippines and Indonesia was undecorated, pottery in the New Guinea region was finely decorated with geometric designs arranged in horizontal bands. In other respects the pottery preserved the red slip and the vessel forms characteristic of earlier Austronesian pottery in Indonesia. Evidently, Austronesian settlers in the New Guinea region got the idea of "tattooing" their pots, perhaps inspired by geometric designs that they had already been using on their bark cloth and body tattoos. This style is termed Lapita pottery, after an archaeological site named Lapita, where it was described.

The much more significant distinguis.h.i.+ng feature of early Austronesian sites in the New Guinea region is their distribution. In contrast to those in the Philippines and Indonesia, where even the earliest known Austronesian sites are on big islands like Luzon and Borneo and Celebes, sites with Lapita pottery in the New Guinea region are virtually confined to small islets fringing remote larger islands. To date, Lapita pottery has been found at only one site (Aitape) on the north coast of New Guinea itself, and at a couple of sites in the Solomons. Most Lapita sites of the New Guinea region are in the Bismarcks, on islets off the coast of the larger Bismarck islands, occasionally on the coasts of the larger islands themselves. Since (as we shall see) the makers of Lapita pottery were capable of sailing thousands of miles, their failure to transfer their villages a few miles to the large Bismarck islands, or a few dozen miles to New Guinea, was certainly not due to inability to get there.

The basis of Lapita subsistence can be reconstructed from the garbage excavated by archaeologists at Lapita sites. Lapita people depended heavily on seafood, including fish, porpoises, sea turtles, sharks, and sh.e.l.lfish. They had pigs, chickens, and dogs and ate the nuts of many trees (including coconuts). While they probably also ate the usual Austronesian root crops, such as taro and yams, evidence of those crops is hard to obtain, because hard nut sh.e.l.ls are much more likely than soft roots to persist for thousands of years in garbage heaps.

Naturally, it is impossible to prove directly that the people who made Lapita pots spoke an Austronesian language. However, two facts make this inference virtually certain. First, except for the decorations on the pots, the pots themselves and their a.s.sociated cultural paraphernalia are similar to the cultural remains found at Indonesian and Philippine sites ancestral to modern Austronesian-speaking societies. Second, Lapita pottery also appears on remote Pacific islands with no previous human inhabitants, with no evidence of a major second wave of settlement subsequent to that bringing Lapita pots, and where the modern inhabitants speak an Austronesian language (more of this below). Hence Lapita pottery may be safely a.s.sumed to mark Austronesians' arrival in the New Guinea region.

What were those Austronesian pot makers doing on islets adjacent to bigger islands? They were probably living in the same way as modern pot makers lived until recently on islets in the New Guinea region. In 1972 I visited such a village on Malai Islet, in the Sia.s.si island group, off the medium-sized island of Umboi, off the larger Bismarck island of New Britain. When I stepped ash.o.r.e on Malai in search of birds, knowing nothing about the people there, I was astonished by the sight that greeted me. Instead of the usual small village of low huts, surrounded by large gardens sufficient to feed the village, and with a few canoes drawn up on the beach, most of the area of Malai was occupied by two-story wooden houses side by side, leaving no ground available for gardens-the New Guinea equivalent of downtown Manhattan. On the beach were rows of big canoes. It turned out that Malai islanders, besides being fishermen, were also specialized potters, carvers, and traders, who lived by making beautifully decorated pots and wooden bowls, transporting them in their canoes to larger islands and exchanging their wares for pigs, dogs, vegetables, and other necessities. Even the timber for Malai canoes was obtained by trade from villagers on nearby Umboi Island, since Malai does not have trees big enough to be fas.h.i.+oned into canoes.

In the days before European s.h.i.+pping, trade between islands in the New Guinea region was monopolized by such specialized groups of canoe-building potters, skilled in sailing without navigational instruments, and living on offsh.o.r.e islets or occasionally in mainland coastal villages. By the time I reached Malai in 1972, those indigenous trade networks had collapsed or contracted, partly because of compet.i.tion from European motor vessels and aluminum pots, partly because the Australian colonial government forbade long-distance canoe voyaging after some accidents in which traders were drowned. I would guess that the Lapita potters were the inter-island traders of the New Guinea region in the centuries after 1600 B.C. B.C.

The spread of Austronesian languages to the north coast of New Guinea itself, and over even the largest Bismarck and Solomon islands, must have occurred mostly after Lapita times, since Lapita sites themselves were concentrated on Bismarck islets. Not until around A.D. A.D. I did pottery derived from the Lapita style appear on the south side of New Guinea's southeast peninsula. When Europeans began exploring New Guinea in the late 19th century, all the remainder of New Guinea's south coast still supported populations only of Papuan-language speakers, even though Austronesian-speaking populations were established not only on the southeastern peninsula but also on the Aru and Kei Islands (lying 7080 miles off western New Guinea's south coast). Austronesians thus had thousands of years in which to colonize New Guinea's interior and its southern coast from nearby bases, but they never did so. Even their colonization of North New Guinea's coastal fringe was more linguistic than genetic: all northern coastal peoples remained predominantly New Guineans in their genes. At most, some of them merely adopted Austronesian languages, possibly in order to communicate with the long-distance traders who linked societies. I did pottery derived from the Lapita style appear on the south side of New Guinea's southeast peninsula. When Europeans began exploring New Guinea in the late 19th century, all the remainder of New Guinea's south coast still supported populations only of Papuan-language speakers, even though Austronesian-speaking populations were established not only on the southeastern peninsula but also on the Aru and Kei Islands (lying 7080 miles off western New Guinea's south coast). Austronesians thus had thousands of years in which to colonize New Guinea's interior and its southern coast from nearby bases, but they never did so. Even their colonization of North New Guinea's coastal fringe was more linguistic than genetic: all northern coastal peoples remained predominantly New Guineans in their genes. At most, some of them merely adopted Austronesian languages, possibly in order to communicate with the long-distance traders who linked societies.

THUS, THE OUTCOME of the Austronesian expansion in the New Guinea region was opposite to that in Indonesia and the Philippines. In the latter region the indigenous population disappeared-presumably driven off, killed, infected, or a.s.similated by the invaders. In the former region the indigenous population mostly kept the invaders out. The invaders (the Austronesians) were the same in both cases, and the indigenous populations may also have been genetically similar to each other, if the original Indonesian population supplanted by Austronesians really was related to New Guineans, as I suggested earlier. Why the opposite outcomes? of the Austronesian expansion in the New Guinea region was opposite to that in Indonesia and the Philippines. In the latter region the indigenous population disappeared-presumably driven off, killed, infected, or a.s.similated by the invaders. In the former region the indigenous population mostly kept the invaders out. The invaders (the Austronesians) were the same in both cases, and the indigenous populations may also have been genetically similar to each other, if the original Indonesian population supplanted by Austronesians really was related to New Guineans, as I suggested earlier. Why the opposite outcomes?

The answer becomes obvious when one considers the differing cultural circ.u.mstances of Indonesia's and New Guinea's indigenous populations. Before Austronesians arrived, most of Indonesia was thinly occupied by hunter-gatherers lacking even polished stone tools. In contrast, food production had already been established for thousands of years in the New Guinea highlands, and probably in the New Guinea lowlands and in the Bismarcks and Solomons as well. The New Guinea highlands supported some of the densest populations of Stone Age people anywhere in the modern world.

Austronesians enjoyed few advantages in competing with those established New Guinean populations. Some of the crops on which Austronesians subsisted, such as taro, yams, and bananas, had probably already been independently domesticated in New Guinea before Austronesians arrived. The New Guineans readily integrated Austronesian chickens, dogs, and especially pigs into their food-producing economies. New Guineans already had polished stone tools. They were at least as resistant to tropical diseases as were Austronesians, because they carried the same five types of genetic protections against malaria as did Austronesians, and some or all of those genes evolved independently in New Guinea. New Guineans were already accomplished seafarers, although not as accomplished as the makers of Lapita pottery. Tens of thousands of years before the arrival of Austronesians, New Guineans had colonized the Bismarck and Solomon Archipelagoes, and a trade in obsidian (a volcanic stone suitable for making sharp tools) was thriving in the Bismarcks at least 18,000 years before the Austronesians arrived. New Guineans even seem to have expanded recently westward against the Austronesian tide, into eastern Indonesia, where languages spoken on the islands of North Halmahera and of Timor are typical Papuan languages related to some languages of western New Guinea.

In short, the variable outcomes of the Austronesian expansion strikingly ill.u.s.trate the role of food production in human population movements. Austronesian food-producers migrated into two regions (New Guinea and Indonesia) occupied by resident peoples who were probably related to each other. The residents of Indonesia were still hunter-gatherers, while the residents of New Guinea were already food producers and had developed many of the concomitants of food production (dense populations, disease resistance, more advanced technology, and so on). As a result, while the Austronesian expansion swept away the original Indonesians, it failed to make much headway in the New Guinea region, just as it also failed to make headway against Austroasiatic and Tai-Kadai food producers in tropical Southeast Asia.

We have now traced the Austronesian expansion through Indonesia and up to the sh.o.r.es of New Guinea and tropical Southeast Asia. In Chapter 19 we shall trace it across the Indian Ocean to Madagascar, while in Chapter 15 we saw that ecological difficulties kept Austronesians from establis.h.i.+ng themselves in northern and western Australia. The expansion's remaining thrust began when the Lapita potters sailed far eastward into the Pacific beyond the Solomons, into an island realm that no other humans had reached previously. Around 1200 B.C. B.C. Lapita potsherds, the familiar triumvirate of pigs and chickens and dogs, and the usual other archaeological hallmarks of Austronesians appeared on the Pacific archipelagoes of Fiji, Samoa, and Tonga, over a thousand miles east of the Solomons. Early in the Christian era, most of those same hallmarks (with the notable exception of pottery) appeared on the islands of eastern Polynesia, including the Societies and Marquesas. Further long overwater canoe voyages brought settlers north to Hawaii, east to Pitcairn and Easter Islands, and southwest to New Zealand. The native inhabitants of most of those islands today are the Polynesians, who thus are the direct descendants of the Lapita potters. They speak Austronesian languages closely related to those of the New Guinea region, and their main crops are the Austronesian package that included taro, yams, bananas, coconuts, and breadfruit. Lapita potsherds, the familiar triumvirate of pigs and chickens and dogs, and the usual other archaeological hallmarks of Austronesians appeared on the Pacific archipelagoes of Fiji, Samoa, and Tonga, over a thousand miles east of the Solomons. Early in the Christian era, most of those same hallmarks (with the notable exception of pottery) appeared on the islands of eastern Polynesia, including the Societies and Marquesas. Further long overwater canoe voyages brought settlers north to Hawaii, east to Pitcairn and Easter Islands, and southwest to New Zealand. The native inhabitants of most of those islands today are the Polynesians, who thus are the direct descendants of the Lapita potters. They speak Austronesian languages closely related to those of the New Guinea region, and their main crops are the Austronesian package that included taro, yams, bananas, coconuts, and breadfruit.

With the occupation of the Chatham Islands off New Zealand around A.D. A.D. 1400, barely a century before European "explorers" entered the Pacific, the task of exploring the Pacific was finally completed by Asians. Their tradition of exploration, lasting tens of thousands of years, had begun when Wiwor's ancestors spread through Indonesia to New Guinea and Australia. It ended only when it had run out of targets and almost every habitable Pacific island had been occupied. 1400, barely a century before European "explorers" entered the Pacific, the task of exploring the Pacific was finally completed by Asians. Their tradition of exploration, lasting tens of thousands of years, had begun when Wiwor's ancestors spread through Indonesia to New Guinea and Australia. It ended only when it had run out of targets and almost every habitable Pacific island had been occupied.

TO ANYONE INTERESTED in world history, human societies of East Asia and the Pacific are instructive, because they provide so many examples of how environment molds history. Depending on their geographic homeland, East Asian and Pacific peoples differed in their access to domesticable wild plant and animal species and in their connectedness to other peoples. Again and again, people with access to the prerequisites for food production, and with a location favoring diffusion of technology from elsewhere, replaced peoples lacking these advantages. Again and again, when a single wave of colonists spread out over diverse environments, their descendants developed in separate ways, depending on those environmental differences. in world history, human societies of East Asia and the Pacific are instructive, because they provide so many examples of how environment molds history. Depending on their geographic homeland, East Asian and Pacific peoples differed in their access to domesticable wild plant and animal species and in their connectedness to other peoples. Again and again, people with access to the prerequisites for food production, and with a location favoring diffusion of technology from elsewhere, replaced peoples lacking these advantages. Again and again, when a single wave of colonists spread out over diverse environments, their descendants developed in separate ways, depending on those environmental differences.

For instance, we have seen that South Chinese developed indigenous food production and technology, received writing and still more technology and political structures from North China, and went on to colonize tropical Southeast Asia and Taiwan, largely replacing the former inhabitants of those areas. Within Southeast Asia, among the descendants or relatives of those food-producing South Chinese colonists, the Yumbri in the mountain rain forests of northeastern Thailand and Laos reverted to living as hunter-gatherers, while the Yumbri's close relatives the Vietnamese (speaking a language in the same sub-subfamily of Austroasiatic as the Yumbri language) remained food producers in the rich Red Delta and established a vast metal-based empire. Similarly, among Austronesian emigrant farmers from Taiwan and Indonesia, the Punan in the rain forests of Borneo were forced to turn back to the hunter-gatherer lifestyle, while their relatives living on Java's rich volcanic soils remained food producers, founded a kingdom under the influence of India, adopted writing, and built the great Buddhist monument at Borobudur. The Austronesians who went on to colonize Polynesia became isolated from East Asian metallurgy and writing and hence remained without writing or metal. As we saw in Chapter 2, though, Polynesian political and social organization and economies underwent great diversification in different environments. Within a millennium, East Polynesian colonists had reverted to hunting-gathering on the Chathams while building a protostate with intensive food production on Hawaii.

When Europeans at last arrived, their technological and other advantages enabled them to establish temporary colonial domination over most of tropical Southeast Asia and the Pacific islands. However, indigenous germs and food producers prevented Europeans from settling most of this region in significant numbers. Within this area, only New Zealand, New Caledonia, and Hawaii-the largest and most remote islands, lying farthest from the equator and hence in the most nearly temperate (Europelike) climates-now support large European populations. Thus, unlike Australia and the Americas, East Asia and most Pacific islands remain occupied by East Asian and Pacific peoples.

CHAPTER 18

HEMISPHERES COLLIDING

THE LARGEST POPULATION REPLACEMENT OF THE LAST 13,000 years has been the one resulting from the recent collision between Old World and New World societies. Its most dramatic and decisive moment, as we saw in Chapter 3, occurred when Pizarro's tiny army of Spaniards captured the Inca emperor Atahuallpa, absolute ruler of the largest, richest, most populous, and administratively and technologically most advanced Native American state. Atahuallpa's capture symbolizes the European conquest of the Americas, because the same mix of proximate factors that caused it was also responsible for European conquests of other Native American societies. Let us now return to that collision of hemispheres, applying what we have learned since Chapter 3. The basic question to be answered is: why did Europeans reach and conquer the lands of Native Americans, instead of vice versa? Our starting point will be a comparison of Eurasian and Native American societies as of 13,000 years has been the one resulting from the recent collision between Old World and New World societies. Its most dramatic and decisive moment, as we saw in Chapter 3, occurred when Pizarro's tiny army of Spaniards captured the Inca emperor Atahuallpa, absolute ruler of the largest, richest, most populous, and administratively and technologically most advanced Native American state. Atahuallpa's capture symbolizes the European conquest of the Americas, because the same mix of proximate factors that caused it was also responsible for European conquests of other Native American societies. Let us now return to that collision of hemispheres, applying what we have learned since Chapter 3. The basic question to be answered is: why did Europeans reach and conquer the lands of Native Americans, instead of vice versa? Our starting point will be a comparison of Eurasian and Native American societies as of A.D. A.D. 1492, the year of Columbus's "discovery" of the Americas. 1492, the year of Columbus's "discovery" of the Americas.

OUR COMPARISON BEGINS with food production, a major determinant of local population size and societal complexity-hence an ultimate factor behind the conquest. The most glaring difference between American and Eurasian food production involved big domestic mammal species. In Chapter 9 we encountered Eurasia's 13 species, which became its chief source of animal protein (meat and milk), wool, and hides, its main mode of land transport of people and goods, its indispensable vehicles of warfare, and (by drawing plows and providing manure) a big enhancer of crop production. Until waterwheels and windmills began to replace Eurasia's mammals in medieval times, they were also the major source of its "industrial" power beyond human muscle power-for example, for turning grindstones and operating water lifts. In contrast, the Americas had only one species of big domestic mammal, the llama / alpaca, confined to a small area of the Andes and the adjacent Peruvian coast. While it was used for meat, wool, hides, and goods transport, it never yielded milk for human consumption, never bore a rider, never pulled a cart or a plow, and never served as a power source or vehicle of warfare. with food production, a major determinant of local population size and societal complexity-hence an ultimate factor behind the conquest. The most glaring difference between American and Eurasian food production involved big domestic mammal species. In Chapter 9 we encountered Eurasia's 13 species, which became its chief source of animal protein (meat and milk), wool, and hides, its main mode of land transport of people and goods, its indispensable vehicles of warfare, and (by drawing plows and providing manure) a big enhancer of crop production. Until waterwheels and windmills began to replace Eurasia's mammals in medieval times, they were also the major source of its "industrial" power beyond human muscle power-for example, for turning grindstones and operating water lifts. In contrast, the Americas had only one species of big domestic mammal, the llama / alpaca, confined to a small area of the Andes and the adjacent Peruvian coast. While it was used for meat, wool, hides, and goods transport, it never yielded milk for human consumption, never bore a rider, never pulled a cart or a plow, and never served as a power source or vehicle of warfare.

That's an enormous set of differences between Eurasian and Native American societies-due largely to the Late Pleistocene extinction (extermination?) of most of North and South America's former big wild mammal species. If it had not been for those extinctions, modern history might have taken a different course. When Cortes and his bedraggled adventurers landed on the Mexican coast in 1519, they might have been driven into the sea by thousands of Aztec cavalry mounted on domesticated native American horses. Instead of the Aztecs' dying of smallpox, the Spaniards might have been wiped out by American germs transmitted by disease-resistant Aztecs. American civilizations resting on animal power might have been sending their own conquistadores to ravage Europe. But those hypothetical outcomes were foreclosed by mammal extinctions thousands of years earlier.

Those extinctions left Eurasia with many more wild candidates for domestication than the Americas offered. Most candidates disqualify themselves as potential domesticates for any of half a dozen reasons. Hence Eurasia ended up with its 13 species of big domestic mammals and the Americas with just its one very local species. Both hemispheres also had domesticated species of birds and small mammals-the turkey, guinea pig, and Muscovy duck very locally and the dog more widely in the Americas; chickens, geese, ducks, cats, dogs, rabbits, honeybees, silkworms, and some others in Eurasia. But the significance of all those species of small domestic animals was trivial compared with that of the big ones.

Eurasia and the Americas also differed with respect to plant food production, though the disparity here was less marked than for animal food production. In 1492 agriculture was widespread in Eurasia. Among the few Eurasian hunter-gatherers lacking both crops and domestic animals were the Ainu of northern j.a.pan, Siberian societies without reindeer, and small hunter-gatherer groups scattered through the forests of India and tropical Southeast Asia and trading with neighboring farmers. Some other Eurasian societies, notably the Central Asian pastoralists and the reindeer-herding Lapps and Samoyeds of the Arctic, had domestic animals but little or no agriculture. Virtually all other Eurasian societies engaged in agriculture as well as in herding animals.

Agriculture was also widespread in the Americas, but hunter-gatherers occupied a larger fraction of the Americas' area than of Eurasia's. Those regions of the Americas without food production included all of northern North America and southern South America, the Canadian Great Plains, and all of western North America except for small areas of the U.S. Southwest that supported irrigation agriculture. It is striking that the areas of Native America without food production included what today, after Europeans' arrival, are some of the most productive farmlands and pastures of both North and South America: the Pacific states of the United States, Canada's wheat belt, the pampas of Argentina, and the Mediterranean zone of Chile. The former absence of food production in these lands was due entirely to their local paucity of domesticable wild animals and plants, and to geographic and ecological barriers that prevented the crops and the few domestic animal species of other parts of the Americas from arriving. Those lands became productive not only for European settlers but also, in some cases, for Native Americans, as soon as Europeans introduced suitable domestic animals and crops. For instance, Native American societies became renowned for their mastery of horses, and in some cases of cattle and sheepherding, in parts of the Great Plains, the western United States, and the Argentine pampas. Those mounted plains warriors and Navajo sheepherders and weavers now figure prominently in white Americans' image of American Indians, but the basis for that image was created only after 1492. These examples demonstrate that the sole missing ingredients required to sustain food production in large areas of the Americas were domestic animals and crops themselves.

In those parts of the Americas that did support Native American agriculture, it was constrained by five major disadvantages vis-a-vis Eurasian agriculture: widespread dependence on protein-poor corn, instead of Eurasia's diverse and protein-rich cereals; hand planting of individual seeds, instead of broadcast sowing; tilling by hand instead of plowing by animals, which enables one person to cultivate a much larger area, and which also permits cultivation of some fertile but tough soils and sods that are difficult to till by hand (such as those of the North American Great Plains); lack of animal manuring to increase soil fertility; and just human muscle power, instead of animal power, for agricultural tasks such as thres.h.i.+ng, grinding, and irrigation. These differences suggest that Eurasian agriculture as of 1492 may have yielded on the average more calories and protein per person-hour of labor than Native American agriculture did.

SUCH DIFFERENCES IN food production const.i.tuted a major ultimate cause of the disparities between Eurasian and Native American societies. Among the resulting proximate factors behind the conquest, the most important included differences in germs, technology, political organization, and writing. Of these, the one linked most directly to the differences in food production was germs. The infectious diseases that regularly visited crowded Eurasian societies, and to which many Eurasians consequently developed immune or genetic resistance, included all of history's most lethal killers: smallpox, measles, influenza, plague, tuberculosis, typhus, cholera, malaria, and others. Against that grim list, the sole crowd infectious diseases that can be attributed with certainty to pre-Columbian Native American societies were nonsyphilitic treponemas. (As I explained in Chapter 11, it remains uncertain whether syphilis arose in Eurasia or in the Americas, and the claim that human tuberculosis was present in the Americas before Columbus is in my opinion unproven.) food production const.i.tuted a major ultimate cause of the disparities between Eurasian and Native American societies. Among the resulting proximate factors behind the conquest, the most important included differences in germs, technology, political organization, and writing. Of these, the one linked most directly to the differences in food production was germs. The infectious diseases that regularly visited crowded Eurasian societies, and to which many Eurasians consequently developed immune or genetic resistance, included all of history's most lethal killers: smallpox, measles, influenza, plague, tuberculosis, typhus, cholera, malaria, and others. Against that grim list, the sole crowd infectious diseases that can be attributed with certainty to pre-Columbian Native American societies were nonsyphilitic treponemas. (As I explained in Chapter 11, it remains uncertain whether syphilis arose in Eurasia or in the Americas, and the claim that human tuberculosis was present in the Americas before Columbus is in my opinion unproven.) This continental difference in harmful germs resulted paradoxically from the difference in useful livestock. Most of the microbes responsible for the infectious diseases of crowded human societies evolved from very similar ancestral microbes causing infectious diseases of the domestic animals with which food producers began coming into daily close contact around 10,000 years ago. Eurasia harbored many domestic animal species and hence developed many such microbes, while the Americas had very few of each. Other reasons why Native American societies evolved so few lethal microbes were that villages, which provide ideal breeding grounds for epidemic diseases, arose thousands of years later in the Americas than in Eurasia; and that the three regions of the New World supporting urban societies (the Andes, Mesoamerica, and the U.S. Southeast) were never connected by fast, high-volume trade on the scale that brought plague, influenza, and possibly smallpox to Europe from Asia. As a result, even malaria and yellow fever, the infectious diseases that eventually became major obstacles to European colonization of the American tropics, and that posed the biggest barrier to the construction of the Panama Ca.n.a.l, are not American diseases at all but are caused by microbes of Old World tropical origin, introduced to the Americas by Europeans.

Rivaling germs as proximate factors behind Europe's conquest of the Americas were the differences in all aspects of technology. These differences stemmed ultimately from Eurasia's much longer history of densely populated, economically specialized, politically centralized, interacting and competing societies dependent on food production. Five areas of technology may be singled out: First, metals-initially copper, then bronze, and finally iron-were used for tools in all complex Eurasian societies as of 1492. In contrast, although copper, silver, gold, and alloys were used for ornaments in the Andes and some other parts of the Americas, stone and wood and bone were still the princ.i.p.al materials for tools in all Native American societies, which made only limited local use of copper tools.

Second, military technology was far more potent in Eurasia than in the Americas. European weapons were steel swords, lances, and daggers, supplemented by small firearms and artillery, while body armor and helmets were also made of solid steel or else of chain mail. In place of steel, Native Americans used clubs and axes of stone or wood (occasionally copper in the Andes), slings, bows and arrows, and quilted armor, const.i.tuting much less effective protection and weaponry. In addition, Native American armies had no animals to oppose to horses, whose value for a.s.saults and fast transport gave Europeans an overwhelming advantage until some Native American societies themselves adopted them.

Third, Eurasian societies enjoyed a huge advantage in their sources of power to operate machines. The earliest advance over human muscle power was the use of animals-cattle, horses, and donkeys-to pull plows and to turn wheels for grinding grain, raising water, and irrigating or draining fields. Waterwheels appeared in Roman times and then proliferated, along with tidal mills and windmills, in the Middle Ages. Coupled to systems of geared wheels, those engines harnessing water and wind power were used not only to grind grain and move water but also to serve myriad manufacturing purposes, including crus.h.i.+ng sugar, driving blast furnace bellows, grinding ores, making paper, polis.h.i.+ng stone, pressing oil, producing salt, producing textiles, and sawing wood. It is conventional to define the Industrial Revolution arbitrarily as beginning with the harnessing of steam power in 18th-century England, but in fact an industrial revolution based on water and wind power had begun already in medieval times in many parts of Europe. As of 1492, all of those operations to which animal, water, and wind power were being applied in Eurasia were still being carried out by human muscle power in the Americas.

Long before the wheel began to be used in power conversion in Eurasia, it had become the basis of most Eurasian land transport-not only for animal-drawn vehicles but also for human-powered wheelbarrows, which enabled one or more people, still using just human muscle power, to transport much greater weights than they could have otherwise. Wheels were also adopted in Eurasian pottery making and in clocks. None of those uses of the wheel was adopted in the Americas, where wheels are attested only in Mexican ceramic toys.

The remaining area of technology to be mentioned is sea transport. Many Eurasian societies developed large sailing s.h.i.+ps, some of them capable of sailing against the wind and crossing the ocean, equipped with s.e.xtants, magnetic compa.s.ses, sternpost rudders, and cannons. In capacity, speed, maneuverability, and seaworthiness, those Eurasian s.h.i.+ps were far superior to the rafts that carried out trade between the New World's most advanced societies, those of the Andes and Mesoamerica. Those rafts sailed with the wind along the Pacific coast. Pizarro's s.h.i.+p easily ran down and captured such a raft on his first voyage toward Peru.

IN ADDITION TO their germs and technology, Eurasian and Native American societies differed in their political organization. By late medieval or Renaissance times, most of Eurasia had come under the rule of organized states. Among these, the Habsburg, Ottoman, and Chinese states, the Mogul state of India, and the Mongol state at its peak in the 13th century started out as large polyglot amalgamations formed by the conquest of other states. For that reason they are generally referred to as empires. Many Eurasian states and empires had official religions that contributed to state cohesion, being invoked to legitimize the political leaders.h.i.+p and to sanction wars against other peoples. Tribal and band societies in Eurasia were largely confined to the Arctic reindeer herders, the Siberian hunter-gatherers, and the hunter-gatherer enclaves in the Indian subcontinent and tropical Southeast Asia. their germs and technology, Eurasian and Native American societies differed in their political organization. By late medieval or Renaissance times, most of Eurasia had come under the rule of organized states. Among these, the Habsburg, Ottoman, and Chinese states, the Mogul state of India, and the Mongol state at its peak in the 13th century started out as large polyglot amalgamations formed by the conquest of other states. For that reason they are generally referred to as empires. Many Eurasian states and empires had official religions that contributed to state cohesion, being invoked to legitimize the political leaders.h.i.+p and to sanction wars against other peoples. Tribal and band societies in Eurasia were largely confined to the Arctic reindeer herders, the Siberian hunter-gatherers, and the hunter-gatherer enclaves in the Indian subcontinent and tropical Southeast Asia.

The Americas had two empires, those of the Aztecs and Incas, which resembled their Eurasian counterparts in size, population, polyglot makeup, official religions, and origins in the conquest of smaller states. In the Americas those were the sole two political units capable of mobilizing resources for public works or war on the scale of many Eurasian states, whereas seven European states (Spain, Portugal, England, France, Holland, Sweden, and Denmark) had the resources to acquire American colonies between 1492 and 1666. The Americas also held many chiefdoms (some of them virtually small states) in tropical South America, Mesoamerica beyond Aztec rule, and the U.S. Southeast. The rest of the Americas was organized only at the tribal or band level.

The last proximate factor to be discussed is writing. Most Eurasian states had literate bureaucracies, and in some a significant fraction of the populace other than bureaucrats was also literate. Writing empowered European societies by facilitating political administration and economic exchanges, motivating and guiding exploration and conquest, and making available a range of information and human experience extending into remote places and times. In contrast, use of writing in the Americas was confined to the elite in a small area of Mesoamerica. The Inca Empire employed an accounting system and mnemonic device based on knots (termed quipu), but it could not have approached writing as a vehicle for transmitting detailed information.

THUS, EURASIAN SOCIETIES in the time of Columbus enjoyed big advantages over Native American societies in food production, germs, technology (including weapons), political organization, and writing. These were the main factors tipping the outcome of the post-Columbian collisions. But those differences as of in the time of Columbus enjoyed big advantages over Native American societies in food production, germs, technology (including weapons), political organization, and writing. These were the main factors tipping the outcome of the post-Columbian collisions. But those differences as of A.D. A.D. 1492 represent just one snapshot of historical trajectories that had extended over at least 13,000 years in the Americas, and over a much longer time in Eurasia. For the Americas, in particular, the 1492 snapshot captures the end of the independent trajectory of Native Americans. Let us now trace out the earlier stages of those trajectories. 1492 represent just one snapshot of historical trajectories that had extended over at least 13,000 years in the Americas, and over a much longer time in Eurasia. For the Americas, in particular, the 1492 snapshot captures the end of the independent trajectory of Native Americans. Let us now trace out the earlier stages of those trajectories.

Table 18.1 summarizes approximate dates of the appearance of key developments in the main "homelands" of each hemisphere (the Fertile Crescent and China in Eurasia, the Andes and Amazonia and Mesoamerica in the Americas). It also includes the trajectory for the minor New World homeland of the eastern United States, and that for England, which is not a homeland at all but is listed to ill.u.s.trate how rapidly developments spread from the Fertile Crescent.

This table is sure to horrify any knowledgeable scholar, because it reduces exceedingly complex histories to a few seemingly precise dates. In reality, all of those dates are merely attempts to label arbitrary points along a continuum. For example, more significant than the date of the first metal tool found by some archaeologist is the time when a significant fraction of all tools was made of metal, but how common must metal tools be to rate as "widespread"? Dates for the appearance of the same development may differ among different parts of the same homeland. For instance, within the Andean region pottery appears about 1,300 years earlier in coastal Ecuador (3100 B.C. B.C.) than in Peru (1800 B.C. B.C.). Some dates, such as those for the rise of chiefdoms, are more difficult to infer from the archaeological record than are dates of artifacts like pottery or metal tools. Some of the dates in Table 18.1 are very uncertain, especially those for the onset of American food production. Nevertheless, as long as one understands that the table is a simplification, it is useful for comparing continental histories.

The table suggests that food production began to provide a large fraction of human diets around 5,000 years earlier in the Eurasian homelands than in those of the Americas. A caveat must be mentioned immediately: while there is no doubt about the antiquity of food production in Eurasia, there is controversy about its onset in the Americas. In particular, archaeologists often cite considerably older claimed dates for domesticated plants at c.o.xcatlan Cave in Mexico, at Guitarrero Cave in Peru, and at some other American sites than the dates given in the table. Those claims are now being reevaluated for several reasons: recent direct radiocarbon dating of crop remains themselves has in some cases been yielding younger dates; the older dates previously reported were based instead on charcoal thought to be contemporaneous with the plant remains, but possibly not so; and the status of some of the older plant remains as crops or just as collected wild plants is uncertain. Still, even if plant domestication did begin earlier in the Americas than the dates shown in Table 18.1, agriculture surely did not provide the basis for most human calorie intake and sedentary existence in American homelands until much later than in Eurasian homelands.

TABLE 18.1 Historical Trajectories of Eurasia and the Americas 18.1 Historical Trajectories of Eurasia and the Americas

Approximate Date of Adoption

Eurasia

Fertile Crescent China England Plant domestication 8500 B.C. B.C.

by 7500 B.C. B.C.

3500 B.C. B.C.

Animal domestication 8000 B.C. B.C.

by 7500 B.C. B.C.

3500 B.C. B.C.

Pottery 7000 B.C. B.C.

by 7500 B.C. B.C.

3500 B.C. B.C.

Villages 9000 B.C. B.C.

by 7500 B.C. B.C.

3000 B.C. B.C.

Chiefdoms 5500 B.C. B.C.

4000 B.C. B.C.

2500 B.C. B.C.

Widespread metal tools or artifacts (copper and/or bronze) 4000 B.C. B.C.

2000 B.C. B.C.

2000 B.C. B.C.

States 3700 B.C. B.C.

2000 B.C. B.C.

500 A.D. A.D.

Writing 3200 B.C. B.C.

by 1300 B.C. B.C.

A.D. 43 43 Widespread iron tools 900 B.C. B.C.

500 B.C. B.C.

650 B.C. B.C.

This table gives approximate dates of widespread adoption of significant developments in three Eurasian and four Native American areas. Dates for animal domestication neglect dogs, which were domesticated earlier than food-producing animals in both Eurasia and the Americas. Chiefdoms are inferred from archaeological evidence, such as ranked burials, architecture, and settlement patterns. The table greatly simplifies a complex ma.s.s of historical facts: see the text for some of the many important caveats.