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Stephen J Marshall

Publications and source records attributed to Stephen J Marshall.

2 recordsLinked to original sources

Human evolution in Polynesia.

The number of eastern Polynesian females required to found the Maori population of Aotearoa (New Zealand) has been recalculated. Our estimates use computer simulations that incorporate realistic sigmoid population growth models and include previously published and new mitochondrial DNA (mtDNA) 3' hypervariable region 1 sequences from Măori (N = 109) and other eastern Polynesian (N = 125) volunteers. Approximately 190 (170-230) women are estimated to have been present in the founding waka (canoes). This new figure is more than double the previous estimate (Murray-McIntosh et al. 1998). Our claim for a large Maori founding population fits well with Măori oral history and has additional support from Măori paleodemography studies based on fertility estimates (Brewis et al. 1990; Pool 1991). An increasing body of data, including our own, supports the concept of planned multiple settlement voyages to Aotearoa by Polynesian navigators, leading us to suggest that theories for an "accidental discovery" of Aotearoa can now be completely disregarded. Four rare and novel Măori mtDNA haplotypes have been identified in the present study, but we are unable to assign the immediate origin of Măori to an exact Pacific island "homeland" because these haplotypes are not currently known elsewhere in Polynesia. We also discuss briefly the ultimate origin of all Polynesians (including Măori) in a wider context. In general, we support the emerging consensus for Pacific origins most closely encapsulated by the "slow boat" model (Oppenheimer and Richards 2001a). Previously "competing" models for the settlement of Oceania are seen as extremes in a continuum of possibilities with the slow boat representing an "intermediate" model. We suggest that a complete account is now close, incorporating data from all relevant interdisciplinary fields to provide a "synthetic total evidence theory."

Biological Evolution↗

The genetics of alcoholism in Polynesians: alcohol and aldehyde dehydrogenase genotypes in young men.

BACKGROUND: The last 10 years have seen growing recognition of the significance of the genes encoding enzymes responsible for hepatic alcohol metabolism as protective factors in the development of alcoholism. METHODS: We have developed DNA sequencing assays for measuring genetic variation at the alcohol dehydrogenase 2 (ADH2), ADH3, and aldehyde dehydrogenase 2 (ALDH2) loci. These have been used to survey volunteer control subjects from three New Zealand ethnic groups (white, Asian, and Polynesian) and young male alcoholics recruited from white and New Zealand Maori patients in a local treatment program. RESULTS: The allele frequency values for whites and Asians obtained in our study closely match those obtained previously in other laboratories. Our data (the first for Polynesians) are 0.42 for ADH2*2, 0.78 for ADH3*1, and 0.00 for ALDH2*2. In the New Zealand Maori alcoholic patients, the ADH2*2 frequency is significantly lower (0.15; p < 0.01). The frequency of ADH3*1 is also lower in this group (0.60), but this value is not significant (0.05 < p < 0.06). CONCLUSIONS: In young male New Zealand Maori, the ADH2*2 allele is a protective factor against alcoholism even in the absence of ALDH2*2.

Alcohol Dehydrogenase↗