Incluye referencias bibliográficas e índice. CONTENIDO: Patterns and processes of becoming: a framework for understanding animal development. Making new bodies: mechanisms of developmental organization -- Specifying identity: mechanisms of developmental patterning -- Differential gene expression: mechanisms of cell differentiation -- Cell-to-cell communication: mechanisms of morphogenesis -- Stems cells: their potential and their niches -- Gametogenesis and fertilization: the circle of sex. Sex determination and gametogenesis -- Fertilization: beginning a new organism -- Early development: cleavage, gastrulation, and axis formation. Rapid specification in snails and nematodes -- The genetics of axis specification in Drosophila -- Sea urchins and tunicates: deuterostome invertebrates -- Amphibians and fish -- Birds and mammals -- Building with ectoderm: the vertebrate nervous system and epidermis. Neural tube formation and patterning -- Brain growth -- Neural crest cells and axonal specificity -- Ectodermal placodes and the epidermis -- Building with mesoderm and endoderm: organogénesis. Paraxial mesoderm: the somites and their derivatives -- Intermediate and lateral plate mesoderm: heart, blood, and kidneys -- Development of the tetrapod limb -- The endoderm: tubes and organs for digestion and respiration -- Postembryonic development. Metamorphosis: the hormonal reactivation of development -- Regeneration -- Aging and senescence -- Development in wider contexts. Development in health and disease: birth defects, endocrine disruptors, and cancer -- Development and the environment: biotic, abiotic, and symbiotic regulation of development -- Development and evolution: developmental mechanisms of evolutionary change.