The molecular biogeography of the Indo-Pacific: testing hypotheses with multispecies genetic patterns

Aim: To test hypothesized biogeographic partitions of the tropical Indo-Pacific Ocean with phylogeographic data from 56 taxa, and to evaluate the strength and nature of barriers emerging from this test. Location: The Indo-Pacific Ocean. Time Period: Pliocene through the Holocene. Major Taxa Studied: 56 marine species. Methods: We tested eight biogeographic hypotheses for partitioning of the Indo-Pacific using a novel modification to analysis of molecular variance. Putative barriers to gene flow emerging from this analysis were evaluated for pairwise ΦST, and these ΦST distributions were compared to distributions from randomized datasets and simple coalescent simulations of vicariance arising from the Last Glacial Maximum. We then weighed the relative contribution of distance vs. environmental or geographical barriers to pairwise ΦST with a distance-based redundancy analysis (dbRDA). Results: We observed a diversity of outcomes, although the majority of species fit a few broad biogeograp...