This book brings together important essays by the one of the leading philosophers of science at work today. Elisabeth A. Lloyd examines several of the central topics in philosophy of biology, including the structure of evolutionary theory, units of selection, and evolutionary psychology, as well as the Science Wars, feminism and science, and sexuality and objectivity. Lloyd challenges the current evolutionary accounts of the female orgasm and analyzes them for bias. She also offers an innovative analysis of the concept of objectivity. Lloyd analyzes the structure of evolutionary theory and unlocks the puzzle of the units of selection debates into four distinct aspects, illuminating several mysteries in the biology literature. Central to all essays in this book is the author’s abiding concern for evidence and empirical data. "Although I do not agree with some of the conclusions the author draws, she certainly provides and interesting perspective and illustrates the importance of being very clear about the nature of the debate and our assumptions when comparing theory and data." Suzanne H. Alonzo, The Quarterly Review of Biology This book examines central topics in philosophy of biology and challenges much of the current thinking. Elisabeth A. Lloyd is Arnold and Maxine Tanis Chair of History and Philosophy of Science and Professor of Biology at Indiana University and an Affiliated Faculty Scholar at the Kinsey Institute for Research in Sex, Gender, and Reproduction. She is the author of The Structure and Confirmation of Evolutionary Theory, Keywords in Evolutionary Biology, and most recently, The Case of the Female Orgasm: Bias in the Science of Evolution.