So much has happened since the Ninth Edition of Developmental Biology was published! The key word in developmental biology for the past three years has been “integration.” The mechanisms of transcriptional gene regulation, the mechanisms of aging, the data on amniote limb development, the ways in which fertilization occurs, the mechanisms of sex determination—all have been “integrated.” Even developmentally important genes have been “integrated” into genetic regulatory networks. The new Tenth Edition of Developmental Biology reflects this exciting new age of genomics, genetic regulatory networks, and digital visualization techniques, while keeping focus on the major questions of animal development.