Lynn Margulis, Distinguished Professor in the Department of Geo‐ sciences at the University of Massachusetts at Amherst, has been a member of the National Academy of Sciences since 1983. She is best known for her pathbreaking work on the bacterial origins of cell organelles and for her collaboration with James Lovelock on Gaia theory.Her previous books include Symbiosis in Cell Evolution; Five Kingdoms (with K. V. Schwartz); and (with Dorion Sagan) Origins of Sex; Garden of Microbial Delights; What Is Life?; What Is Sex?; and Slanted Truths: Essays on Gaia, Symbiosis and Evolution. Her current activity is spying on, filming, and writing scientific papers on the lives of protoctists and other microcosmic beings with whom we share our planet.