This study will test three hypotheses concerning the processes that drive diversification of tropical organisms. These hypotheses have been widely discussed and have specific predictions that should be broadly applicable to tropical organisms. Dr. Ulrich Mueller and Scott Solomon will use three species of leafcutter ants in the genus Atta for this project. Specimens will be collected throughout the geographic range of each species, and genetic analyses, conducted in the United States and in Brazil, will test each prediction in turn.
This project will be the first to test these hypotheses with invertebrates, a group that comprises the majority of diversity in many tropical ecosystems. Furthermore, leafcutter ants are a fundamental component of many tropical habitats, and some species are major agricultural pests. By documenting genetic diversity within three such species, this analysis that could reveal the presence of new, cryptic species. Finally, the elucidation of the patterns by which new species are formed is critical for the establishment of effective conservation strategies, since the goal of conservation is to preserve not only existing diversity but also the processes by which diversity is generated.
