Geography and Demography
The islands of Oceania are divided into three large geographic areas. Polynesia occupies an enormous triangle in the eastern and central Pacific, stretching from Hawaii in the north, to French Polynesia and Easter Island in the east, to New Zealand in the west.
Melanesia encompasses the western island chains that lie south of the equator and extend from New Guinea to New Caledonia and Fiji. Micronesia includes the groups of islands that lie west of Polynesia and north of Melanesia. Although Polynesia is spread widely across the Pacific, the physical environments — whether volcanic high islands or coral atolls — are all quite similar in being lushly vegetated and almost all rich in food resources from land and sea. Melanesia has the greatest variety of physical environments: mountain rain forests, grassy plateaus, gorges and valleys, low jungles and alluvial plains, mosquito-ridden riverine and coastal swamps, sandy beaches, volcanic fields, and earthquake-prone rifts. In western Micronesia, weathered volcanic islands are interspersed among small, lush coral atolls. Farther to the east (Marshall Islands and Kiribati), the Micronesian atolls are generally much drier and larger. Except for temperate New Zealand and arid or temperate Australia, the climate of Oceania remains generally hot and humid year-round. It is generally accepted that Oceania and Australia were populated by waves of immigrants initially from Southeast Asia (Oliver 1962; Howe 1984; Marshall 1984). In fact, it was over 30,000 years ago that Southeast Asian huntergatherers crossed land bridges and narrow channels into New Guinea, Australia, and Tasmania. Intermigration among these landmasses was curtailed around 8,000 years ago, when New Guinea and Tasmania became separate islands.A later wave of Malay-type Iiorticulturalists from islands of Southeast Asia invaded the coasts and rivers of New Guinea about 6,000 years ago, bringing root crops, pigs, chickens, dogs, and polished tools.
These agriculturalists then spread out through the islands of Melanesia around 3,000 to 4,000 years ago in their sailing canoes. At this same time, other Southeast Asian agriculturalists migrated from the Philippine Islands to Yap and the Mariana Islands and from Sulawesi to Palau, thus settling the high islands of western Micronesia. After the voyagers had settled the major islands of Melanesia, they pushed north from Vanuatu into Kiribati, thence into the Marshall Islands, and finally into the Caroline Islands about 2,000 years ago. As Micronesia was thus being settled, other voyagers advanced from Fiji east to Samoa and Tonga around 3,000 years ago. From this cradle, they moved out through the rest of eastern Polynesia - to the Marquesas 2,000 years ago and from there to the Society, Cook, and Hawaiian Islands around A.D. 600, New Zealand around A.D. 750, and Tokelau and Tuvalu and assorted scattered outliers after A.D. 1000.With rare exception, these Pacific Basin island people were gardeners and fisherfolk, supplementing their diet with various parts of wild plants, small animals of the beach or bush, or pigs and chickens that they raised. Most lived in small hamlets of close relatives, although sizable villages were to be found especially on the coasts of the larger islands. The Australian aborigines were nomadic within circumscribed territories. Like the aboriginal Australians, the New Zealand Maori were hunters and gatherers without pigs or chickens, yams or taro. Unlike the Australians, the Maori lived in large settlements and had sweet potato and fem root as well as a rich variety of birds, reptiles, and fish to eat (Oliver 1962).
Water supplies were often limited throughout most of the region (Henderson et al. 1971). Atoll dwellers were without rivers or lakes, and had to rely on rain catchment or brackish pools. The volcanic islands generally had freshwater sources, but settlements near them caused pollution, and people living on ridgetops above them had to transport the water over long distances. Water kept near shelters was easily contaminated. Lack of abundant freshwater for washing resulted in poor hygiene.