I am focused on solving one of the most enduring puzzles in evolutionary biology: how processes operating among individual organisms scale up to generate large-scale patterns of biodiversity. I have primarily approached this problem by examining the footprint of evolutionary processes in phylogenetic trees. Phylogenies and interspecific data provide unique information about how evolution has unfolded over deep time. By fitting statistical models to phylogenetic trees, we can gain insight into the long-term dynamics of multiple evolutionary processes working together—in this way, phylogenetic studies can complement theoretical, observational, and experimental studies in which the temporal scale is usually much shorter. The converse is also true: because the time scale of phylogenetic data is so long, many of the details of evolutionary history will be obscured. The grand challenge of my work is to reconcile disparate types of data and observations at multiple time-scales to form a coherent view of evolutionary change.
In my research group, we develop mathematical theory, statistical methods, and computational tools to test evolutionary hypotheses using phylogenetic trees. We use these to address a wide variety of questions, such as why organisms differ in number of chromosomes, why some groups are more diverse than others, and why communities are structured the way they are. To complement this work, we also develop general informatics tools for handling, manipulating, and sharing biodiversity data.