In this book, Rudolf A. Raff reaches out to the scientifically queasy, using his life story and his growth as a scientist to illustrate why science matters, especially at a time when many Americans are both suspicious of science and hostile to scientific ways of thinking. Noting that science has too often been the object of controversy in school curriculums and debates on public policy issues ranging from energy and conservation to stem-cell research and climate change, Raff argues that when the public is confused or ill-informed, these issues tend to be decided on religious, economic, and political grounds that disregard the realities of the natural world. Speaking up for science and scientific literacy, Raff tells how and why he became an evolutionary biologist and describes some of the vibrant and living science of evolution. Once We All Had Gills is also the story of evolution writ large: its history, how it is studied, what it means, and why it has become a useful target in a cultural war against rational thought and the idea of a secular, religiously tolerant nation.