DNA sequence data from multiple parts of the genome now provide a wealth of data for inferring phylogenetic relationships. Recently, a large number of new statistical methods have been developed to analyze data from these multiple independent loci. However, these new “species tree” methods have not been rigorously compared, especially for closely related species. Our project will use a well-studied bird genus (New World orioles, Icterus), as well as two poorly known genera from Australia (butcherbirds, Cracticus; red robins, Petroica) to compare the performance of species tree methods as applied to recently diverged animal species.

Advances in the use of DNA sequencing in systematics have made Darwin’s vision of a “Tree of Life” showing evolutionary relationships among all organisms a feasible goal. Previously, virtually all molecular phylogenies (evolutionary trees) for closely related animals were based on maternally inherited mitochondrial DNA sequences. This project used orioles as a model group to test the utility of combining multiple nuclear intron sequences as a basis for constructing whole genome trees for all closely related animal species. The resulting evolutionary trees have been used to reconstruct the history of female color evolution in orioles. We demonstrated that the ancestral oriole was likely a tropical species with elaborate color in both males and females. Northern migratory species such as the Baltimore Oriole have independently lost elaborate female color.