What comes first, form or function? Trumpeted as the future of biological science, evolutionary developmental biology (or "evo-devo") answers this fundamental question by showing how evolution controls the development of organisms. In Forms of Becoming, Alessandro Minelli, a leading international figure in the field, takes an in-depth and comprehensive look at the history and key issues of evo-devo. Spirited and insightful, this book focuses 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. Presenting the accessible and cutting-edge ideas of evolutionary developmental biology, Forms of Becoming is fascinating reading for anyone interested in genetics and the animal form.