Animals diverge from common ancestry through changes in their DNA, but what are the genes that control morphology? In this landmark work, the author team led by Dr. Sean Carroll presents the general principles of the genetic basis of morphological change through a synthesis of evolutionary biology with genetics and embryology. The text first addresses the history of animal evolution, model system developmental genetics, and genetic regulatory mechanisms, and then examines case studies of evolutionary change at different genetic and morphological levels. In this extensively revised second edition, the authors delve into the latest discoveries, incorporating new coverage of comparative genomics, molecular evolution of regulatory proteins and elements, and microevolution of animal development. This new edition also includes major insights from recent genome studies, incorporates new findings from evo-devo biology research, and adds a new chapter focusing on models of variation and divergence among closely related species. An engaging style, clear, four-color illustrations, and up-to-date content all combine to make this text a highly accessible and definitive synthesis of the field.