Reticulate Evolution Influenced the Andean Hummingbird Radiation

Although it is well recognized that gene flow is intimately associated with the diversification of closely related species, it remains unclear whether hybrization between distantly related species in different genera contributes to the radiation of species. Hummingbirds (Trochilidae) are a large monophyletic clade (~330 species) that colonized a wide variety of habitats in the Neotropical and Nearctic regions. Our analysis of complete mitochondria and 2,949 nuclear loci of 46 species representing the nine major clades shows discordance between mitogenome and Z chromosome gene-based phylogenies, and nuclear topologies. The latter do not support the sister relationship of the mostly Andean brilliant and coquette clades. Such discordance could result from incomplete lineage sorting or introgression. We found that introgression did occur between recent genera of brilliants and coquettes, constituting the first molecular evidence of divergence in face of gene-flow in hummingbirds.