Evolutionary Trees and Their Uses

Many members of our lab group have reconstructed phylogenies for groups of birds or other organisms and then used them to test broader questions about diversification and trait evolution. A sample of our current and past studies includes:

comparative analysis exampleGraduate student Nick Mason has used phylogenetic comparative methods to study the evolution of vocal signals and plumage variation in tanagers (avian family Thraupidae). Nick continues to work on various projects that involve inferring and subsequently using trees to study interesting traits in passerine birds, such as cavity nesting and migration in Old-world flycatchers, species limits in redpoll finches, phylogeography in Horned Larks, and clutch sizes in New Guinean songbirds.

Graduate student Jake Berv also generates and uses phylogenies for various groups of birds. He has recently built a comprehensive phylogeny of the cotingas (an incredibly diverse family of passerine birds) in collaboration with Richard Prum of Yale University, to explore hypotheses about the potential relationships between sexual dimorphism and breeding systems. Jake is simultaneously working on other projects that compare the biogeographic histories of neotropical grassland birds and explore the deep relationships in the avian tree of life. In general, Jake is interested in studying gene-tree species-tree discordance, comparative methods, and applying phylogenetic tools to both deep and shallow scale evolutionary questions.

PrintIrby continues to work on evolutionary questions in the wood-warblers (avian family Parulidae). A number of years ago, that endeavor also led to a broader, multi-institution collaboration on the entire ‘emberizoid’ radiation of about 800 songbird species, with partners Keith Barker and Scott Lanyon of U. Minnesota, Kevin Burns of San Diego State, and John Klicka of U. Washington. We have used this phylogeny extensively to study diversification patterns (with Dan Rabosky), community ecology (with Wes Hochachka), vocal behavior (with Andy Farnsworth), migration biology (with Ben Winger), and other traits.

diversification rate graphIrby, Dustin Rubenstein (now at Columbia U.), and Carlos Botero (Now at U. New Mexico) also have pursued a long-term collaboration on the comparative biology of the Mimidae (mockingbirds, thrashers, and allies) and Sturnidae (starlings and mynas), in which we have used phylogenies to test hypotheses about the ecology of cooperative breeding, the evolution of song complexity, and the various social correlates of sexual selection.

A project led by Dan Rabosky (now at the University of Michigan) in partnership with numerous Australian scientists explored the evolutionary history and ecology of Ctenotus skinks, testing patterns in their diversification and community ecology. This project has now largely moved with Dan, as he continues to study this and other systems around the world.

A project led by Katie Wagner (formerly a graduate student at Cornell advised by Amy McCune, now at the University of Wyoming) explored phylogenetics and gene flow in a radiation of cichlid fish from Lake Tanganyika. Katie continues to use this cichlid system to test hypotheses about how species originate and diversify in rapid radiations.

Relevant publications

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