摘要

Background: The presence of ecological opportunity can trigger adaptive radiation. Freshwater colonization of marine ancestors during the post-glacial dispersal could have triggered adaptive radiation in the threespine stickleback (Gasterosteus aculeatus). Japanese marine threespine stickleback can be classified into two genetically divergent groups, the Pacific Ocean group and the Japan Sea group. %26lt;br%26gt;Question: Are all Japanese freshwater threespine stickleback populations derived from the Pacific Ocean lineage? Or are some freshwater populations derived from the evolutionarily divergent Japan Sea lineage? %26lt;br%26gt;Methods: We collected stickleback from 22 different locations across Japan, including nine freshwater populations, five Pacific Ocean anadromous populations, and eight Japan Sea anadromous populations. We determined the genotypes for 11 different microsatellite markers. We created phylogenies using different measures of genetic distance based on both allele frequencies and allele lengths. We inferred population structure using Bayesian analysis. %26lt;br%26gt;Results: All freshwater populations analysed were genetically similar to the Pacific Ocean anadromous populations, suggesting that they are likely derived from the Pacific Ocean lineage rather than the Japan Sea lineage.

  • 出版日期2013-3