Research in Dr. McMahon's lab focuses on the analysis of biological diversity, particularly through phylogenetic systematics of plants. Lab-based work includes comparative molecular sequencing, aimed at inferring evolutionary relationships among lineages in the legume family (Fabaceae), and using the resulting phylogenies to infer historical rates and modes of floral morphological evolution. Computational research includes testing data from public molecular sequence databases for the ability to construct large-scale phylogenetic trees for all 1.7 million known species, investigating theoretical limits to phylogenetic inference, and developing software for analyzing the effects of fragmentation in phylogenetic and phylogenomic data sets