Dr. Peter Raven is director of the Missouri Botanical Garden and Engelmann Professor of Botany at Washington University. A distinguished scientist, Dr. Raven is a member of the National Academy of Sciences, the National Research Council, and is a MacArthur and a Guggenheim fellow. He has received numerous honors and awards for his botanical research and work in tropical conservation, including the National Medal of Science. In addition to coauthoring this text, Raven has authored twenty other books and several hundred scientific articles.

Jonathan Losos is a professor in the Department of Biology at Washington University and is also chair of the undergraduate Environmental Studies program. An evolutionary biologist, Losos's research has focused on studying patterns of adaptive radiation and evolutionary diversification in lizards. The recipient of several awards including the prestigious Theodosius Dobzhanksy and David Starr Jordan Prizes for outstanding young evolutionary biologists, Losos has published more than eighty scientific articles. He is currently the editor of the American Naturalist, a leading journal integrating the fields of evolutionary biology, behavior and ecology.

George Johnson is professor emeritus of biology at Washington University in St. Louis, where he has taught genetics and general biology to undergraduates for 30 years. Also professor of genetics at Washington University School of Medicine, he is a student of population genetics and evolution. He has authored more than fifty scientific publications, and several high school and college texts, including The Living World, a very successful non-majors college biology text. He has pioneered the development of interactive CD-ROM and web-based investigations for biology teaching.

Susan Singer is professor of biology at Carleton College in Northfield, Minnesota, where she has taught introductory biology, plant biology, plant development, and developmental genetics for 18 years. Her research interests are focused on the development and evolution of flowering plants. Singer has authored numerous scientific publications on plant development, contributed chapters to developmental biology texts, and been actively involved with the education efforts of several professional societies. She serves on the NRC Committee on Undergraduate Science Education.