I study biological diversity and phylogeny. Phylogeny (life’s evolutionary tree) is the large-scale history of genetic descent, and as such is central to the interpretation and organization of information on all characteristics of organisms, from structure and physiology to genomics. Much of my work develops analytical methods by which to understand evolutionary process from this genetic history. In addition, I write software to make such methods available to biologists. I also apply these approaches: through extensive field and lab work, we have resolved the first comprehensive phylogeny for the largest family of spiders, the salticids. Their phylogeny indicates this is a rather young group, with independent evolutionary radiations occurring on different continents since their isolation.