In and out of Mesoamerica: temporal divergence ofAmaziliahummingbirds pre‐dates the orthodox account of the completion of theIsthmus ofPanama

Abstract

AbstractAimWe used mitochondrialDNAsequences to reconstruct the phylogenetic relationships of MesoamericanAmaziliahummingbirds (Trochilidae). The phylogeny was used to identify vicariance scenarios, reconstruct ancestral biogeographical areas, and investigate the role of geological events in generating genetic divergence through vicariance events.LocationMesoamerica.MethodsMolecular sequence data were gathered from three mitochondrial genes (ND2,ND5and12S) for samples taken within the Mesoamerican region and analysed using maximum parsimony, maximum‐likelihood andBayesian approaches. Statistical dispersal–vicariance analysis (S‐DIVA) was used to reconstruct biogeographical areas and changes in distribution during the evolutionary history ofAmazilia. The phylogeny was calibrated using fossil dates, mean substitution rates and coalescent‐based divergence time inference.ResultsAmaziliacan be split into two divergent lineages, with high levels of sequence divergence within someMesoamerican species. Ancestral area reconstructions favour an ancestral distribution west of the Isthmus of Tehuantepec, with subsequent dispersals east of the isthmus and to South America. Divergence time estimations suggest that major diversification events occurred in theMiocene andPliocene, corresponding temporally and geographically to the formation of the mountain systems and establishment of the major biomes inMesoamerica.Main conclusionsThe diversification ofAmaziliacorresponds to vegetation shifts in combination with regional orogenesis. Intriguingly, the timing of the major diversification events and dispersal intoSouthAmerica pre‐dates the completion of thePanamanian isthmusc. 4 Ma before present.