Concerted Pleistocene dispersal and genetic differentiation in passerine birds from the Tres Marías Archipelago, Mexico

Studies in evolutionary biology have commonly been focused on insular systems because of their natural geographic isolation and relatively simpler biotas. Using mitochondrial DNA sequences of 4 passerine bird species distributed in the Tres Marias Archipelago (TMA) and the nearby mainland of western Mexico—Cardinalis cardinalis, Turdus rufopalliatus, Vireo hypochryseus, and Icterus pustulatus—we determined interspecific and intraspecific phylogenetic relationships between insular and mainland populations, conducted insular age-based time calibration for the estimation of divergence times, and used Bayesian analyses to examine the colonization history of islands. Specifically, we tested whether the study species from the TMA share the same colonization history since the emergence of the islands ∼120 kya, taking advantage of the reduced isolation due to sea-level fluctuations during the Pleistocene, or whether there were independent colonization events. We also looked for evidence in the genetic st...