Cover -- Half-title -- Title -- Copyright -- Dedication -- Contents -- Preface -- Acknowledgements -- CHAPTER ONE The Nature of Development -- Development for the Sake of Development -- Developmental Competition between Body Parts -- The Robustness of Morphogenesis -- CHAPTER TWO Everything Begun to the Service of Development: Cellular Darwinism and the Origin of Animal Form -- Cilia, Cell Division, and Morphogenesis -- Epithelia without Cilia -- Origin of the Ecdysozoan Cuticle -- Cuticle, Body Size, and Internal Fertilisation -- Origin of Mineralised Skeletons -- Organic Matrices -- Coda -- CHAPTER THREE Development: Generic to Genetic -- Developmental Genes -- Master Control Genes? -- Self-Assembly or Cytotaxis? -- Default Morphology -- Generic Forms -- A Bestiary of Generic Forms -- The Earthworm and the Ankylosaurus -- Deceptive Numbers -- Genetic Assimilation -- Genes and Phenotype -- Evolutionary Dissociation between Genes and Phenotypes -- A Role for the 'Developmental Genes' -- The Hox Code -- Organic Codes -- Universal Genetic Tools -- Genetic Networks and Morphogenesis -- CHAPTER FOUR Periodisation -- The Primacy of Time -- Time Schedule: Synchronous Versus Metachronous -- Units in Time -- Homology of Developmental Stages or Events -- Comparing Stages -- What Is a Larva? -- Metamorphosis as Metagenesis -- Postembryonic Development -- One Life throughout the Metamorphosis -- Developmental Stages as Units of Competition? -- Number of Moults, Dyar's Coefficient, and Targeted Growth -- Lazarus Developmental Features -- Recapitulation -- CHAPTER FIVE Body Regions: Their Boundaries and Complexity -- Tagmosis -- Instability of Tagmatic Boundaries -- Homology of Tagmata -- Number of Tagmata and Convergence -- The Complexity of Postembryonic Development -- Williston's Rule -- Developmental Time and Body Axes.

The Time Axis of Development and the Patterning of the Proximo-Distal Axis of the Appendages -- Topology -- Morphology and Developmental Topology -- Topology of Coaptations -- Topological Breakdown -- CHAPTER SIX Differentiation and Patterning -- Cells as Units of Differentiation -- Cell Cycle Length -- Cell Types -- Cell Autonomy, Induction, and Repatterning -- Cell Contacts and Cell Communication -- Asymmetric Cell Divisions -- Positional Homology and the Hot Spots of Differentiation -- Positional Information or Informational Position? -- Zootype and the Patterning of the Nervous System -- Cellularity and Positional Information -- Transpatterning -- Provisional Scaffolding -- Segments, Vertebrae, and Scales -- Guidelines to Follow -- Phylotypic Stage and Phylotypic Period -- Morphological Assimilation in Ontogeny and Phylogeny -- Patterning in Regeneration -- Embryonic Patterning Versus Patterning in Regeneration -- Terminal or Apical Control Versus Regeneration -- CHAPTER SEVEN Size Factors -- Cell Size Critical for Morphogenesis -- Size and Cell Number in Embryonic Anlagen -- Early Because Small or Small Because Early? -- Critical Number of Cells in Embryonic Anlagen -- Miniaturisation -- Miniaturisation and Body Patterning -- Miniaturisation, Segments, and Cells -- CHAPTER EIGHT Axes and Symmetries -- The Animal's Main Body Axis -- Polyps, Sipunculans, and Squids -- The Dual Animal -- Sipunculans and ParaHox Genes -- Morphological Versus Functional Polarity -- Cartesian Axes, or Not -- The Syntax of the Body -- What Is a Tail? -- The Time Arrow of Growth and Differentiation -- The Beginnings of Animal Polarity -- Tapeworm Polarity -- Differentiating Back to Front -- Polarity Reversal -- Axis Paramorphism and Origin of the Appendages -- Axis Paramorphism -- Terminal Control and Axis Paramorphism -- Gene Co-option -- Limbs and Genitalia.

Symmetry and Asymmetry -- Directional Asymmetry -- CHAPTER NINE Segments -- What Is a Segment? -- Virtual Versus Physical Segmental Boundaries -- How Many Times Did Metazoans Evolve Segmentation? -- Reconstructing Urbilateria -- Segments in Annelids, Arthropods, and Vertebrates -- Limits of a Typological View of Segments -- Segmentation: One Animal, More than One Mechanism -- Double Segmentation: Eosegments and Merosegments -- The Naupliar-Postnaupliar-Meromeric Model of Arthropod Segmentation -- Reliable Patterning of Eosegments and the Variable Schedule of Merosegmentation -- Heterogeneous Segments in Vertebrates and Annelids -- Germ Layers and Segmentation -- Segmental Mismatches and Resegmentation -- Dorso-Ventral Mismatches -- Resegmentation -- CHAPTER TEN Evo-devo Perspectives on Homology -- Concepts and Interpretations -- Hierarchies and Beyond -- Homology: Absolute or Relative? -- Temporal Serial Homology -- Genes and Homology -- Genetic Redundancy, Network Degeneracy, and Homology -- Evolutionary Novelties -- Units of Description and Comparison -- Modules -- Evolutionary Changes in the Discernibility of Developmental Modules: Fusion Versus Non-disjunction -- Germ Layers and Homology -- Lesser Developmental Units -- Frames of Reference: Muscles and Nerves -- Muscles and Homology -- Nerves and Homology -- Summary and Conclusions -- References -- Index.