This uniquely comprehensive study analyzes genetic and cultural variation in a human population of extraordinary diversity. The author measures the relationship between patterns of biological and patterns of cultural variation as a way to test the contribution made by natural selection to genetic variability. If linguistic similarity and migration history serve to predict biological patterns, support is provided for the hypothesis that forces other than natural selection are responsible for the diversity observed.

The data for this study come from a group of eighteen villages located in eight neighboring language areas that are clustered in a small region of Bougainville Island, Papua New Guinea. Biological and anthropological data are analyzed with a battery of sophisticated statistical and taxonomic methods: multiple discriminant analyses, principal coordinates analyses, principal components analyses, and Gower's R2 comparison. Diverse biological properties of the Bougainville Islanders prove to be closely related to their patterns of migration. Although this result in no way refutes the role of natural selection in the evolutionary process, it highlights the extent to which genetic diversity can be molded, at least in human populations, by nonselective events.