No abstract

The population structure of a fruit fly, Zeugodacus tau, was studied by a Single-Strand Conformation Polymorphism (SSCP) technique. Twenty haplotypes of Cytochrome Oxidase unit I (COI) sequence were found in flies collected from Southern Thailand. The phylogenetic tree and haplotype network revealed gene flow across a large geographic range. With the aid of winds, their gene flow diminished population structure. The population size of Z. tau in Southern Thailand seemed to be large and stable, but the other populations in some locations had experienced a bottleneck effect, leading to local genetic differentiation. Fruit flies from the eastern areas had large effective population sizes, whereas the populations from other areas were smaller. This pattern matched the ecological niche centroid model, in which fruit flies disperse from high population areas to lower ones.