About the Author Peter H. Raven, Ph.D., is director of the Missouri Botanical Garden and Engelmann professor of botany at Washington University at St. Louis. He oversees the garden's internationally recognized research program in tropical botany--one of the world's most active in the study and conservation of imperiled tropical habitats. Raven's botanical research and work in the area of tropical conservation have earned him numerous honors and awards, including a MacArthur Fellowship. He has written 17 textbooks and more than 400 articles, and he is a member of th National Academy of Science and the National Research Council. Jonathan Losos is a Monique and Philip Lehner Professor for the Study of Latin America in the Department of Organismic and Evolutionary Biology and Curator of Herpetology at the Museum of Comparative Zoology at Harvard University. Losos's research has focused on studying patterns of adaptive ratiation and evolutionary diversification in lizards. The recipient of several awards including hte prestigious Theodosius Dobzhansky and David Starr Jordan Prizes for outstanding young evolutionary biologists, Losos has published more than 100 scientific articles. Kenneth A. Mason received his undergraduate degree in Molecular Biology from the University of Washington, worked at UC Berkeley, then pursued his PhD in Genetics at UC Davis. He has taught Gentics, Microbial Genetics, Microbiology, Advanced Molecular Genetics, Introductory Biology, and a Genetics Laboratory that he designed. Tod Duncan is a Clinical Assistant Professor at the University of Colorado Denver. He currently teaches firstsemester general biology and coordinates first and second semester general biology laboratories. Previously,he taught general microbiology, virology, the biology of cancer, medical microbiology, and cell biology. Abachelor’s degree in cell biology with an emphasis on plant molecular and cellular biology from the Universityof East