Until recently, a small number of model organisms has been the focus of most research in molecular, cellular, and developmental biology. But in the last few years, due in part to increased interest in questions of evolution, technical advances in selectively altering gene expression patterns, and the reduced costs of genome sequencing, the range of organisms used for research is greatly expanding. Emerging Model Organisms, Volume 1, introduces the reader to this new generation of model organisms, providing a diverse catalog of potential species useful for extending research in new directions. In this volume leading experts provide chapters on 23 emerging model systems, ranging from bat and butterfly to cave fish and choanoflagellates; cricket and finch to quail, snail, and tomato. Subsequent releases of the Emerging Model Organisms series, already in preparation, will focus on additional species. Material is also available in CSH Protocols: www.cshprotocols.org/emo