David Sepkoski is a senior research scholar at the Max Planck Institute for the History of Science. He is the author of Rereading the Fossil Record: The Growth of Paleobiology as an Evolutionary Discipline, also published by the University of Chicago Press. Michael Ruse is the Lucyle T. Werkmeister Professor of Philosophy and director of the Program in the History and Philosophy of Science at Florida State University. He is the author or editor of nearly thirty books, including The Gaia Hypothesis: Science on a Pagan Planet, also published by the University of Chicago Press.