Arnold I. Miller is Professor in the Department of Geology, University of Cincinnati. A unifying thread in Miller’s research is an interest in biodiversity throughout geological time and in the present day. Currently, a central focus of his work is the interpretation of major changes in global biodiversity during the history of life, including brief intervals of time when global biodiversity dramatically decreased (mass extinctions) or increased (radiations). Recently, he has been collaborating with colleagues in the Departments of Biology and Geography in an investigation of the effects of urbanization on the distribution and abundance of plant species in urban-to-rural settings.