Steven R. Beissinger is professor of conservation biology in the Department of Environmental Science, Policy, and Management and in the Museum of Vertebrate Zoology at the University of California, Berkeley. He is coeditor of Population Viability Analysis, also published by the University of Chicago Press. David D. Ackerly is professor in the Department of Integrative Biology and an associate curator in the Jepson Herbarium at the University of California, Berkeley. Holly Doremus is the James H. House and Hiram H. Hurd Professor of Environmental Regulation at the University of California, Berkeley, School of Law and coauthor of Water War in the Klamath Basin: Macho Law, Combat Biology, and Dirty Politics. Gary E. Machlis is university professor of environmental sustainability at Clemson University and science advisor to the director of the National Park Service.