Population bottlenecks in Polynesia revealed by minisatellites

Abstract

Tandem-repetitive highly variable loci in the human genome (minisatellites) have been used in gene mapping and as DNA “fingerprints”, but they have not yet found much application in population genetics. We have investigated the capacity of six minisatellites to discriminate between four populations in Oceania. We find that in comparison to Melanesians, Polynesians have a significant loss of heterozygosity (or gene diversity), not noted using more traditional markers. We show also that the number of alleles, the allele distribution and the mutation rates at the Polynesian minisatellite loci do not deviate from those predicted by the neutral mutation/infinite allele model. The low gene diversity is therefore likely to be a result of the maintenance of small population sizes and bottleneck effects during the colonization of the Pacific.