I am interested in the diversity of life: How many species are there? Why are some groups of organisms so much more diverse than others? How do environmental and biological traits influence speciation rate and rates of molecular evolution? Are there large-scale patterns in the history of life? My work involves combining DNA sequence data, organismal traits, information from the fossil record, and comparative analytical methods (the macroevolutionary analog of human twin studies) to address these questions. I additionally contribute to the Barcode of Life campaign and am developing approaches for using these vast DNA sequence resources for broad exploratory and hypothesis-driven biodiversity science. I have a particular focus on aquatic invertebrates and biodiversity of the arctic.