This book investigates the limits and possibilities of mismatch theories in evolutionary medicine, a topic that has not yet received much attention in philosophy.  Mismatch explanations are part of a broader attempt to establish evolutionary thinking as a foundation for human medicine. Although mismatch explanations are well-established in ecology to account for extinction risks, the ongoing attempts to transfer them into human medical contexts are riddled with conceptual and ethical problems. This book offers a comprehensive analysis of the theoretical presuppositions as well as the normative implications associated with mismatch theorizing in evolutionary medicine