What comes first, form or function? Evolutionary developmental biology (or "evo-devo") answers this fundamental question by showing how evolution controls the development of organisms. Alessandro Minelli takes an in-depth and comprehensive look at the history and key issues of evo-devo, focusing on the innovative ways animal organisms evolve through competition and cooperation. Minelli provides a complete overview of conceptual developments--from the fierce nineteenth-century debates between the French biologists Geoffroy and Cuvier, who fought over questions of form versus function--to modern theories of how genes dictate body formation. The book's wide-ranging topics include expression patterns of genes, developmental bias, the role of developmental genes, and genetic determinism. Drawing from diverse examples, such as the anatomy of butterflies, giraffes, Siamese twins, and corals, Minelli extends and reformulates important concepts from development, evolution, and the interplay between the two.