This vol. has its origins in a conference, held October 22-23, 2004, at the Amer. Philosophical Society (APS) Library, Phila. The main focus was on evolutionary studies in America before, during, and after the famous “synthesis” period of the 1930s and 1940s. The synthesis period has been the focus of substantial new research and important new thinking. This vol. brings together 15 specialists to explore these developments and to press further. Questions shaping these essays focus on the following broad themes: Continuity and breaks across generations; Emerging narratives for the period; New research opportunities at the APS; New ideas from the research front; Placing evolutionists in the broader context of biology; and Future directions. Also includes a thoughtful intro. by Michael Ruse.