Australia and New Guinea. Claims that humans have lived in Australia for well in excess of 40,000 years are currently under scrutiny, but a continuous sequence of occupied sites in both Australia and New Guinea only occurs from about 40,000 b.p. onward. Although some people think one entry route might be a move from Timor to the western Australian shore, continuities between plant species and tropical marine faunas suggest New Guinea as the “logical biotic pathway” of initial colonization.

The themes of Pleistocene and early-Holocene archaeology are dictated by the diverse environmental backgrounds of western Melanesia. The continental island of New Guinea is dominated by a steep central cordillera rising in some places to 4,000 meters. Because of rainfall patterns and cloud cover, Pleistocene colonists likely settled the series of intermontane valleys that range between 1,200 and 2,400 meters. These settlers encountered many plants and animals foreign to people accustomed to the tropical coasts, as variations in altitude produced distinct vegetational zones, each with distinctive floral and faunal distributions. The subsistence patterns reflected in excavated sites like the Nombe rock shelter reflect a strategy of hunting and collecting across these different zones.

Although the oldest site on the New Guinea coast, on uplifted coral terraces on the Huon Peninsula, has yielded dates of ca. 40,000 b.p. or a little older, the earliest evidence of humans in the highlands is later, ca. 30,000 b.p., which may reflect the profound behavioral shifts required to colonize these uplands. The forests and grasslands contained mainly small game animals, but Pleistocene New Guinea was also home to a small number of large mammals, all now extinct. At Nombe, four megafaunal species—all forest browsers—existed between ca. 25,000 and ca. 14,000 years ago, but the excavator is ambivalent as to whether the bones are in the site through human action or whether the animals died there by natural causes.

In contrast to game species, the New Guinea Highlands possesses a huge array of plants, including about 200 that today are used for food. Little direct evidence exists for the development of artificial microenvironments to promote the growth of useful plants, plant processing, and perhaps plant storage, but these processes probably developed from the beginning of settlement. The Huon Peninsula site, Nombe, Kosipe, and a range of other early sites have produced a variety of tanged, waisted, and grooved axes, both flaked and ground. These tools were arguably used to thin forest patches by trimming and ring barking in order to promote the growth of useful plants. Early forest burning reflected in the pollen records supports this interpretation.

There are thus hints of a long progression that culminated in a distinctive highlands agriculture that appeared around 9000–6000 b.p. at Kuk in the Wahgi Valley in the highlands of New Guinea. A series of evolutionary stages of garden technology has been developed for the site, each stage reflecting sophisticated hydraulic practices involving both drainage and irrigation, and the series culminated in the familiar root crop/arboriculture systems present in the highlands today. Associated pig husbandry is reflected in the archaeological record between 5000 and 6000 b.p. with some claims going back to 10,000 b.p.

Apart from the obvious physical contrasts between montane and island settlement, the movement into the Bismarck Archipelago first involved humans in adapting to the simplified terrestrial ecology of an oceanic world. New Guinea today supports a total of fifty-two terrestrial mammals of sufficient size to represent potential game; the number shrinks to six in New Britain and New Ireland, of which at least two were probably carried there by humans. Bird and plant numbers also reduce dramatically. People were dependent upon a restricted range of natural resources, the majority of them coastal, which could not support more than low numbers of humans in the long term.

The initial colonists adopted strategies that compensated for this reduced range of edible plants and terrestrial animals by high mobility across a large territory. Such mobility was predicated on safe, durable, and maneuverable watercraft, which took people to the scattered resources rather than moving such resources to the people. However, as population, local resource