Palaeoecology and prehistory in New Guinea

Abstract

Marked differences in climate during the last 30,000 years are reflected in significant changes in vegetational distribution in New Guinea, with the treeline varying from 400–1200 m below the present level. There have been minor fluctuations in climate during the Holocene period and it is probable that rainfall increased in lowland areas following the flooding of the Arafura shelf. Savannah and grassland areas have been maintained over the last 12,000 years in some areas by burning, but more subtle changes produced by human activity still remain to be explored. At the height of the last glaciation, the grassland areas were more than ten times their present area, and the extensive forest-grassland area presented a potential resource for Pleistocene man. Several archaeological sites in highland areas give evidence of exploitation at various times back to 30,000 years B.P. Sites occupied toward the end of the Pleistocene age indicate that mid-montane forest was more attractive than the forest-alpine ecotone. There is now strong evidence for the appearance of agriculture in the highlands about 9000 years ago. About 6000 years ago taro appears to have been cultivated, associated with roughly contemporaneous introduction of the pig. As human exploitation of the land intensified, resources of the bush declined and the gap was filled by increased use of the domesticated economy, including intensification of pig husbandry. This, in turn, led to the pig becoming an item of currency exchange and to the development of the role of big-men in New Guinea society. The introduction of the sweet potato, a few hundred years ago, resulted in intensification of agriculture and extension of the cultivated areas and further development of pig husbandry. The islands and lowland areas present quite different environments to that of the highlands and no sites have been excavated in these areas so far of Pleistocene age. But the lower levels of Balof shelter and Kukuba Cave were occupied by people who did not make pottery. The latter probably was introduced by speakers of Austronesian languages, although pottery did not appear in Balof Shelter until about 2000 year B.P. Between 3500 and 2500 years B.P. a distinctive Lapita-ware pottery has been found in sites from Manus Island across into the central Pacific, but only a single Lapita sherd has been found on the New Guinea mainland. About 2500 years ago Lapita pottery disappeared at the time when a number of localized cultural groups were developing and evidence suggests a “Melanization” of the Lapita people. On the mainland New Guinea pottery sites date to only 2000 years ago and on the south coast the last 1200 years is characterized by long-distance trading. Study of skeletal remains from Nebira and Motupore, on the south coast, dated from 1000 and 300 B.P. has enabled estimates of life expectancy to be made and also shows the presence of anaemia, yaws and leprosy. The two populations also show a striking difference in incidence of dental disease.