Founded in 1975, the Department of Ecology and Evolutionary Biology at University of Arizona was the first department of its kind, pioneering a model for the organization of biology now used in many of the world’s leading universities. Consistent with our mission to explore life’s diversity from genomes to ecosystems, we are the primary department within the College of Science and across the University that seeks to encompass all levels of biological organization, all branches of the tree of life, and all modes of ecological interaction. We are the primary department in which evolution, the most important unifying concept in biology, infuses all facets of its research and training.