In the book, "Embryos, Genes, and Evolution", Raff and co-author Thomas Kaufman proposed a synthesis of developmental and evolutionary biology. In "The Shape of Life", Raff analyzes the rise of this experimental discipline and lays out research questions, hypotheses and approaches to guide its development. Raff uses the evolution of animal body plans to exemplify the interplay between developmental mechanisms and evolutionary patterns. Animal body plans emerged half a billion years ago. Evolution within these body plans during this span of time has resulted in the tremendous diversity of living animal forms. Raff argues for an integrated approach to the study of the intertwined roles of development and evolution involving phylogenetic, comparative and functional biology. This synthesis should interest not only scientists working in these areas, but also paleontologists, zoologists, morphologists, molecular biologists and geneticists.