Phylogenomics of New World Toucans and Barbets: A Model for Understanding Biogeographic History of the Neotropics

This study focuses on the phylogenomic relationships of a monophyletic clade of birds including the toucans (Aves: Ramphastidae) and their relatives, the New World barbets (Aves: Capitonidae) and toucan-barbets (Aves: Semnornithidae). Toucans and their relatives have been models for reconstructing the biogeographic history of the Neotropics. Multiple genera of toucans and their relatives co-occur across the Neotropics and thus these taxa can serve as replicates for testing biogeographic hypotheses. I used both UCE and mitochondrial genome sequences to reconstruct phylogenetic trees and chronograms and then used BioGeoBEARS to map highland/lowland and cis/trans-Andean and Atlantic Forest areas onto these trees. I confirmed previous studies indicating that (1) lowland Selenidera toucanets may be paraphyletic with respect to Andigena mountain-toucans and (2) the toucan barbets (Semnornithidae) are sister to the toucans (Ramphastidae). This ancestral state reconstruction confirmed that the Andes were important in the diversification of both lowland and highland taxa in this group and that lowland taxa dispersed into the Andes seven times. For lowland taxa, there were 8 transitions from the cis-Andean or highland regions to trans-Andean regions and Amazonian taxa likely colonized the Atlantic Forest relatively recently during Pleistocene climatic oscillations. Overall, a combination of data on timing and reconstruction of ancestral areas suggests that although Andean uplift may have been a factor in diversification, the primary driver for both highland and lowland toucan and barbet taxa was dispersal into the Andes from the lowlands, dispersal from the cis-Andean to the Trans-Andean region, and dispersal into the Atlantic Forest from Amazonia.M.S., Environmental Science -- Drexel University, 201