been termed 'firestick farming.' The Aborigines modified and managed the surrounding landscape in ways that increased its production of edible plants and animals, without resorting to cultivation. In particular, they intentionally burned much of the landscape periodically. That served several purposes: the fires drove out animals that could be killed and eaten immediately; fires converted dense thickets into open parkland in which people could travel more easily; the parkland was also an ideal habitat for kangaroos, Australia's prime game animal; and the fires stimulated the growth both of new grass on which kangaroos fed and of fern roots on which Aborigines themselves fed. 310• GUNS, GERMS, AND STEEL We think of Australian Aborigines as desert people, but most of them were not. Instead, their population densities varied with rainfall (because it controls the production of terrestrial wild plant and animal foods) and with abundance of aquatic foods in the sea, rivers, and lakes. The highest population densities of Aborigines were in Australia's wettest and most productive regions: the Murray- Darling river system of the Southeast, the eastern and northern coasts, and the southwestern corner. Those areas also came to support the densest populations of European settlers in modern Australia. The reason we think of Aborigines as desert people is simply that Europeans killed or drove them out of the most desirable areas, leaving the last intact Aboriginal populations only in areas that Europeans didn't want. Within the last 5,000 years, some of those productive regions witnessed an intensification of Aboriginal food-gathering methods, and a buildup of Aboriginal population density. Techniques were developed in eastern Australia for rendering abundant and starchy, but extremely poisonous, cycad seeds edible, by leaching out or fermenting the poison. The previously unexploited highlands of southeastern Australia began to be visited regularly during the summer, by Aborigines feasting not only on cycad nuts and yams but also on huge hibernating aggregations of a migratory moth called the bogong moth, which tastes like a roasted chestnut when grilled. Another type of intensified food-gathering activity that developed was the freshwater eel fisheries of the Murray-Darling river system, where water levels in marshes fluctuate with seasonal rains. Native Australians constructed elaborate systems of canals up to a mile and a half long, in order to enable eels to extend their range from one marsh to another. Eels were caught by equally elaborate weirs, traps set in dead-end side canals, and stone walls across canals with a net placed in an opening of the wall. Traps at different levels in the marsh came into operation as the water. level rose and fell. While the initial construction of those 'fish farms' must have involved a lot of work, they then fed many people. Nineteenth-century European observers found villages of a dozen Aboriginal houses at the eel farms, and there are archaeological remains of villages of up to 146 stone houses, implying at least seasonally resident populations of hundreds of people. Still another development in eastern and northern Australia was the harvesting of seeds of a wild millet, belonging to the same genus as the broomcorn millet that was a staple of early Chinese agriculture. The millet YALI'SPEOPLE • 311 was reaped with stone knives, piled into haystacks, and threshed to obtain the seeds, which were then stored in skin bags or wooden dishes and finally ground with millstones. Several of the tools used in this process, such as the stone reaping knives and grindstones, were similar to the tools independently invented in the Fertile Crescent for processing seeds of other wild grasses. Of all the food-acquiring methods of Aboriginal Australians, millet harvesting is perhaps the one most likely to have evolved eventually into crop production. Along with intensified food gathering in the last 5,000 years came new types of tools. Small stone blades and points provided more length of sharp edge per pound of tool than the large stone tools they replaced. Hatchets with ground stone edges, once present only locally in Australia, became widespread. Shell fishhooks appeared within the last thousand years. why did australia not develop metal tools, writing, and politically complex societies? A major reason is that Aborigines remained hunter-gatherers, whereas, as we saw in Chapters 12-14, those developments arose elsewhere only in populous and economically specialized societies of food producers. In addition, Australia's aridity, infertility, and climatic unpredictability limited its hunter-gatherer population to only a few hundred thousand people. Compared with the tens of millions of people in ancient China or Mesoamerica, that meant that Australia had far fewer potential inventors, and far fewer societies to experiment with adopting innovations. Nor were its several hundred thousand people organized into closely interacting societies. Aboriginal Australia instead consisted of a sea of very sparsely populated desert separating several more productive ecological 'islands,' each of them holding only a fraction of the continent's population and with interactions attenuated by the intervening distance. Even within the relatively moist and productive eastern side of the continent, exchanges between societies were limited by the 1,900 miles from Queensland's tropical rain forests in the northeast to Victoria's temperate rain forests in the southeast, a geographic and ecological distance as great as that from Los Angeles to Alaska. Some apparent regional or continentwide regressions of technology in Australia may stem from the isolation and relatively few inhabitants of its population centers. The boomerang, that quintessential Australian 312 • GUNS, GERMS, AND STEEL weapon, was abandoned in the Cape York Peninsula of northeastern Australia. When encountered by Europeans, the Aborigines of southwestern Australia did not eat shellfish. The function of the small stone points that appear in Australian archaeological sites around 5,000 years ago remains uncertain: while an easy explanation is that they may have been used as spearpoints and barbs, they are suspiciously similar to the stone points and barbs used on arrows elsewhere in the world. If they really were so used, the mystery of bows and arrows being present in modern New Guinea but absent in Australia might be compounded: perhaps bows and arrows actually were adopted for a while, then abandoned, across the Australian continent. All these examples remind us of the abandonment of guns in Japan, of bows and arrows and pottery in most of Polynesia, and of other technologies in other isolated societies (Chapter 13). The most extreme losses of technology in the Australian region took place on the island of Tasmania, 130 miles off the coast of southeastern Australia. At Pleistocene times of low sea level, the shallow Bass Strait now separating Tasmania from Australia was dry land, and the people occupying Tasmania were part of the human population distributed continuously over an expanded Australian continent. When the strait was at last flooded around 10,000 years ago, Tasmanians and mainland Australians became cut off from each other because neither group possessed watercraft capable of negotiating Bass Strait. Thereafter, Tasmania's population of 4,000 hunter-gatherers remained out of contact with all other humans on Earth, living in an isolation otherwise known only from science fiction novels. When finally encountered by Europeans in a.d. 1642, the Tasmanians had the simplest material culture of any people in the modern world. Like mainland Aborigines, they were hunter-gatherers without metal tools. But they also lacked many technologies and artifacts widespread on the mainland, including barbed spears, bone tools of any type, boomerangs, ground or polished stone tools, hafted stone tools, hooks, nets, pronged spears, traps, and the practices of catching and eating fish, sewing, and starting a fire. Some of these technologies may have arrived or been invented in mainland Australia only after Tasmania became isolated, in which case we can conclude that the tiny Tasmanian population did not independently invent these technologies for itself. Others of these technologies were brought to Tasmania when it was still part of the Australian mainland, and were subsequently lost in Tasmania's cultural isolation. For example, YALI'SPEOPLE • 313 the Tasmanian archaeological record documents the disappearance of fishing, and of awls, needles, and other bone tools, around 1500 b.c. On at least three smaller islands (Flinders, Kangaroo, and King) that were isolated from Australia or Tasmania by rising sea levels around
