Assessing the potential for reverse colonization among Japanese birds by mining DNA barcode data

Reverse colonization from an island to a continent runs counter to the classic models of speciation in island biogeography. We mined the Barcode of Life Data Systems and generated mitochondrial DNA-based phylogenetic analyses for 118 Japanese bird species to identify candidates for reverse colonization histories from Japan to mainland Asia. Mitochondrial DNA tree topologies suggested 5 strong and 35 weak candidate species for reverse colonization from Japan to mainland Asia. Thirty-nine mitochondrial DNA topologies contradicted a reverse colonization hypothesis. For the remaining 39 species the ancestral distribution is ambiguous from the available mitochondrial DNA gene tree topology. A combination of geography and climatic and geologic history are likely drivers of avian speciation in the Japanese Islands and subsequent reverse colonization events to mainland Asia. These data highlight the utility of large scale DNA barcoding databases in generating phylogenetic and biogeographic hypotheses.