subequatorial Africa's original Pygmy and Khoisan languages by Bantu languages. Hence East Asia's linguistic upheavals raise a corresponding question: what enabled Sino-Tibetan speakers to spread from North China to South China, and speakers of Austroasiatic and the other original South China language families to spread south into tropical Southeast Asia? Here, we must turn to archaeology for evidence of the technological, political, and agricultural advantages that some Asians evidently gained over other Asians. As everywhere else in the world, the archaeological record in East Asia for most of human history reveals only the debris of hunter-gatherers using unpolished stone tools and lacking pottery. The first East Asian evidence for something different comes from China, where crop remains, bones of domestic animals, pottery, and polished (Neolithic) stone tools appear by around 7500 b.c. That date is within a thousand years of the beginning of the Neolithic Age and food production in the Fertile Crescent. But because the previous millennium in China is poorly known archaeologically, one cannot decide at present whether the origins of Chinese food production were contemporaneous with those in the Fertile Crescent, slightly earlier, or slightly later. At the least, we can say that China was one of the world's first centers of plant and animal domestication. China may actually have encompassed two or more independent centers of origins of food production. I already mentioned the ecological differences between China's cool, dry north and warm, wet south. At a given latitude, there are also ecological distinctions between the coastal lowlands and the interior uplands. Different wild plants are native to these disparate environments and would thus have been variously available to incipient farmers in various parts of China. In fact, the earliest identified crops were two drought-resistant species of millet in North China, but rice in South China, suggesting the possibility of separate northern and southern centers of plant domestication. Chinese sites with the earliest evidence of crops also contained bones of domestic pigs, dogs, and chickens. These domestic animals and crops were gradually joined by China's many other domesticates. Among the animals, water buffalo were most important (for pulling plows), while silkworms, 33o ' GUNS, GERMS, ANDsteel ducks, and geese were others. Familiar later Chinese crops include soybeans, hemp, citrus fruit, tea, apricots, peaches, and pears. In addition, just as Eurasia's east-west axis permitted many of these Chinese animals and crops to spread westward in ancient times, West Asian domesticates also spread eastward to China and became important there. Especially significant western contributions to ancient China's economy have been wheat and barley, cows and horses, and (to a lesser extent) sheep and goats. As elsewhere in the world, in China food production gradually led to the other hallmarks of 'civilization' discussed in Chapters 11-14. A superb Chinese tradition of bronze metallurgy had its origins in the third millennium b.c. and eventually resulted in China's developing by far the earliest cast-iron production in the world, around 500 b.c. The following 1,500 years saw the outpouring of Chinese technological inventions, mentioned in Chapter 13, that included paper, the compass, the wheelbarrow, and gunpowder. Fortified towns emerged in the third millennium b.c., with cemeteries whose great variation between unadorned and luxuriously furnished graves bespeaks emerging class differences. Stratified societies whose rulers could mobilize large labor forces of commoners are also attested by huge urban defensive walls, big palaces, and eventually the Grand Canal (the world's longest canal, over 1,000 miles long), linking North and South China, Writing is preserved from the second millennium b.c. but probably arose earlier. Our archaeological knowledge of China's emerging cities and states then becomes supplemented by written accounts of China's first dynasties, going back to the Xia Dynasty, which arose around 2000 b.c. As for food production's more sinister by-product of infectious diseases, we cannot specify where within the Old World most major diseases of Old World origin arose. However, European writings from Roman and medieval times clearly describe the arrival of bubonic plague and possibly smallpox from the east, so these germs could be of Chinese or East Asian origin. Influenza (derived from pigs) is even more likely to have arisen in China, since pigs were domesticated so early and became so important there. China's size and ecological diversity spawned many separate local cultures, distinguishable archaeologically by their differing styles of pottery and artifacts. In the fourth millennium b.c. those local cultures expanded geographically and began to interact, compete with each other, and MOWCHINA BECAME CHINESE • 331 coalesce. Just as exchanges of domesticates between ecologically diverse regions enriched Chinese food production, exchanges between culturally diverse regions enriched Chinese culture and technology, and fierce competition between warring chiefdoms drove the formation of ever larger and more centralized states (Chapter 14). While China's north-south gradient retarded crop diffusion, the gradient was less of a barrier there than in the Americas or Africa, because China's north-south distances were smaller; and because China's is transected neither by desert, as is Africa and northern Mexico, nor by a narrow isthmus, as is Central America. Instead, China's long east-west rivers (the Yellow River in the north, the Yangtze River in the south) facilitated diffusion of crops and technology between the coast and inland, while its broad east-west expanse and relatively gentle terrain, which eventually permitted those two river systems to be joined by canals, facilitated north-south exchanges. All these geographic factors contributed to the early cultural and political unification of China, whereas western Europe, with a similar area but a more rugged terrain and no such unifying rivers, has resisted cultural and political unification to this day. Some developments spread from south to north in China, especially iron smelting and rice cultivation. But the predominant direction of spread was from north to south. That trend is clearest for writing: in contrast to western Eurasia, which produced a plethora of early writing systems, such as Sumerian cuneiform, Egyptian hieroglyphics, Hittite, Minoan, and the Semitic alphabet, China developed just a single well-attested writing system. It was perfected in North China, spread and preempted or replaced any other nascent system, and evolved into the writing still used in China today. Other major features of North Chinese societies that spread southward were bronze technology, Sino-Tibetan languages, and state formation. All three of China's first three dynasties, the Xia and Shang and Zhou Dynasties, arose in North China in the second millennium b.c. Preserved writings of the first millennium b.c. show that ethnic Chinese already tended then (as many still do today) to feel culturally superior to non-Chinese 'barbarians,' while North Chinese tended to regard even South Chinese as barbarians. For example, a late Zhou Dynasty writer of the first millennium b.c. described China's other peoples as follows: 'The people of those five regions—the Middle states and the Rong, Yi, and other wild tribes around them—had all their several natures, which they could not be made to alter. The tribes on the east were called Yi. They had their 3 3 2 'GUNS,GERMS, AND STEEL hair unbound, and tattooed their bodies. Some of them ate their food without its being cooked by fire.' The Zhou author went on to describe wild tribes to the south, west, and north as indulging in equally barbaric practices, such as turning their feet inward, tattooing their foreheads, wearing skins, living in caves, not eating cereals, and, of course, eating their food raw. States organized by or modeled on that Zhou Dynasty of North China spread to South China during the first millennium b.c., culminating in China's political unification under the Qin Dynasty in 221 b.c. Its cultural unification accelerated during that same period, as literate 'civilized' Chinese states absorbed, or were copied by, the illiterate 'barbarians.' Some of that cultural unification was ferocious: for instance, the first Qin emperor condemned all previously written historical books as worthless and ordered them burned, much to the detriment of our understanding of early Chinese history and writing. Those and other draconian
