Mechanisms of global diversification in the brown booby (Sula leucogaster) revealed by uniting statistical phylogeographic and multilocus phylogenetic methods

Recent theoretical and empirical research suggests that statistical models based on coalescent theory can improve both phylogeographic and phylogenetic inference. An approach that involves elements of both statistical phylogeography (e.g., Isolation with Migration analyses) and multilocus phylogenetic inference (e.g., *BEAST) may be particularly useful when applied to populations with relatively old divergence times. Here we use such an approach in the globally distributed brown booby (Sula leucogaster). We sampled 215 individuals from all major breeding areas and genotyped them at eight microsatellite and three nuclear intron loci. We found that brown booby populations were highly differentiated and that colonies can be grouped into four major genetic populations (Caribbean Sea, Central Atlantic Ocean, Indo-Central Pacific, and Eastern Pacific). These populations apparently diverged in the absence of gene flow and, with one exception, currently exchange few to no migrants. The Eastern ...