Chapter 9. Homo Sapiens is an Evolving Species: Origins of the Austronesians

This paper commences with a survey of genetic markers thought to give protection from malaria, in connection with the issue of differentiation between An and NAn populations in Oceania. The closely-linked, highly polymorphic human leukocyte antigen (HLA) class II genes, HLA-DR and -DQ, are then examined for evidence of in situ evolution in some Austronesian-speaking populations of Oceania. The authors define the evolutionary forces of founder effect, genetic drift, mutation, migration and selection and look for evidence that these evolutionary forces shaped the genetic profiles seen in contemporary populations of Austronesian speakers. Genetic data confirm an ultimate East Asian origin for Polynesians but also indicate some degree of past gene flow from island Melanesian populations.