Thraupidae is the second largest family of birds and represents about 4% of all avian species and 12% of the Neotropical avifauna. Species in this family display a wide range of plumage colors and patterns, foraging behaviors, vocalizations, ecotypes, and habitat preferences. The lack of a complete phylogeny for tanagers has hindered the study of this evolutionary diversity. Here, we present a comprehensive, species-level phylogeny for tanagers using six molecular markers. Our analyses identified 13 major clades of tanagers that we designate as subfamilies. In addition, two species are recognized as distinct branches on the tanager tree. Our topologies disagree in many places with previous estimates of relationships within tanagers, and many long-recognized genera are not monophyletic in our analyses. Our trees identify several cases of convergent evolution in plumage ornaments and bill morphology, and two cases of social mimicry. The phylogeny produced by this study provides a robust framework for studying macroevolutionary patterns and character evolution. We use our new phylogeny to study diversification processes, and find that tanagers show a background model of exponentially declining diversification rates. Thus, the evolution of tanagers began with an initial burst of diversification followed by a rate slowdown. In addition to this background model, two later, clade-specific rate shifts are supported, one increase for Darwin's finches and another increase for some species of Sporophila. The rate of diversification within these two groups is exceptional, even when compared to the overall rapid rate of diversification found within tanagers. This study provides the first robust assessment of diversification rates for the Darwin's finches in the context of the larger group within which they evolved.
Bibliographical noteFunding Information:
We thank the scientific collectors, collection managers, staff, and curators at the following institutions for providing the tissues used in this study: American Museum of Natural History; Academy of Natural Sciences, Philadelphia; University of Minnesota, Bell Museum of Natural History; Colección Ornitológica Phelps; Cornell University Museum of Vertebrates; Universidad del Valle, Colombia; Field Museum of Natural History; Instituto de Investigación de recursos Biológicos Alexander von Humboldt; Instituto de Ciencias Naturales, Universidad Nacional de Colombia; University of Kansas Natural History Museum; Natural History Museum of Los Angeles County; Louisiana State University Museum of Natural Science Collection of Genetic Resources; Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; University of Nevada Las Vegas, Barrick Museum of Natural History; Museum of Vertebrate Zoology, University of California, Berkeley; San Diego State University Museum of Biodiversity, Smithsonian Tropical Research Institute; University of Michigan Museum of Zoology; National Museum of Natural History (Smithsonian Institution); University of Washington, Burke Museum; and Zoological Museum, University of Copenhagen. We thank W. Mauck, R. Sedano, R. Keith, M. Alexander, and T. Shepherd for assistance with lab work. E. Dickinson and L. Christidis provided taxonomic advice. For advice on diversification analyses, we thank D. Rabosky. For suggestions on the manuscript, we thank C. Krajewski and two anonymous reviewers. Some of the photos in the graphical abstract were provided by M. Alexander and L. Calvert. This research was supported by the National Geographic Society (KJB) and the National Science Foundation (IBN-0217817 and DEB-0315416 to KJB; DEB-0315218 to IJL; DEB-0315469 to JK; and DEB-0316092 to SML and FKB). AJS was supported by a National Science Foundation Graduate Research Fellowship (2008074713). Appendix A
- Darwin's finches