Mitochondrial DNA variability of West New Guinea populations

This paper reports human mitochondrial DNA variability in West New Guinea (the least known, western side of the island of New Guinea), not yet de- scribed from a molecular perspective. The study was car- ried out on 202 subjects from 12 ethnic groups, belonging to six different Papuan language families, representative of both mountain and coastal plain areas. Mitochondrial DNA hypervariable region 1 (HVS 1) and the presence of the 9-bp deletion (intergenic region COII-tRNA Lys ) were investigated. HVS 1 sequencing identified 73 polymorphic sites defining 89 haplotypes; the 9-bp deletion, which is considered a marker of Austronesian migration in the Pacific, was found to be absent in the whole West New Guinea study sample. Statistical analysis applied to the resulting haplotypes reveal high heterogeneity and an intersecting distribution of genetic variability in these populations, despite their cultural and geographic diversity. The results of subse- quent phylogenetic approaches subdivide mtDNA diver- sity in West New Guinea into three main clusters (groups I-III), defined by sets of polymorphisms which are also shared by some individuals from Papua New Guinea. Comparisons with worldwide HVS 1 sequences stored in the MitBASE database show the absence of these patterns outside Oceania and a few Indonesian subjects, who also lack the 9-bp deletion. This finding, which is consistent with the effects of genetic drift and prolonged isolation of West New Guinea populations, lead us to regard these patterns as New Guinea population markers, which may harbor the genetic memory of the earliest human migra- tions to the island. Am J Phys Anthropol 117:49 - 67, 2002. © 2002 Wiley-Liss, Inc. New Guinea is Melanesia's most "continental" re- gion, in which a large territory encompassing a number of ecological niches has favored the biocul- tural microdifferentiation of its human populations (Attenborough and Alpers, 1992). Scientific research on the island has mostly fo- cused on Papua New Guinea (PNG), the eastern, formerly Australian half, which has maintained a privileged relationship with the English-speaking scientific community. West New Guinea (WNG), the Indonesian half of the island ("Propinsi Papua," for- merly called Irian Jaya), is on the whole more tra- ditional and much less investigated. Nevertheless, scientific knowledge derived from the study of PNG populations has often been inappropriately ex- tended to the western side of New Guinea, and the island has thus been viewed as representing a single evolutionary scenario. However, although New Guinea is a geographic and cultural unit, WNG shows peculiar features of its own which deserve greater attention.