Preface; Acknowledgements; Part I. Introduction: 1.1 A developmental approach to an evolutionary problem; 1.2 The early history of the animal kingdom; 1.3 Alternative strategies; 1.4 Creation versus destruction; 1.5 Systematics and the concept of natural classification; 1.6 Micromutation versus macromutation; 1.7 Developing organisms as inverted cones; Part II. What is a Body Plan?: 2.1 Body plans and taxonomic levels; 2.2 Body plans, cladograms and homology; 2.3 Body plans and embryology; 2.4 Body plans, genes and mutations; 2.5 Body plans, adaptation and environments; Part III. Patterns of Body Plan Origins: 3.1 Strategy; 3.2 Patterns of metazoan inter-relationships; 3.3 Early fossils: from cladograms to trees; 3.4 Bringing back morphology; 3.5 Paleoecology and possible adaptive scenarios; Part IV. Evolutionary Developmental Biology: 4.1 From pattern to mechanism; 4.2 The aims of Evolutionary Developmental Biology; 4.3 A brief history; 4.4 Is there a theory of development?; Part V. Developmental Mechanisms: Cells and Signals: 5.1 Strategy; 5.2 Cellular processes and architecture; 5.3 Short-range signals: cell-cell contacts; 5.4 Mid-range signals and the nature of 'morphogens'; 5.5 Long-range signals and pan-organismic co-ordination; 5.6 Patterns of interconnection: developmental programmes; Part VI. Developmental Mechanisms: Genes: 6.1 Introduction; 6.2 Overview of the genetics of Drosophila body axes; 6.3 The Antennapedia and Bithorax complexes; 6.4 The hedgehog gene and limb development; 6.5 Developmental programmes and an evolutionary message; Part VII. Comparative Developmental Genetics: 7.1 From development to evolution; 7.2 Phylogeny of Hox genes; 7.3 Dorso-ventral polarity in arthropods and chordates; 7.4 Limb formation, hedgehog, and the nature of homology; 7.5 Phylogeny of cadherin genes; 7.6 Emergent evolutionary messages; Part VIII. Gene Duplication and Mutation: 8.1 Introduction; 8.2 The creation of new genes; 8.3 Mutation: the classical approach; 8.4 Mutation: a developmental approach; 8.5 Mutation and the evolution of development; Part IX. The Spread of Variant Ontogenies in Populations: 9.1 Introduction; 9.2 Population genetic models of directional selection; 9.3 Internal selection; 9.4 The origin of body plans: a population perspective; 9.5 Types of genetic change; 9.6 Drift, drive and directed mutation; Part X. Creation Versus Destruction: 10.1 A fourth 'eternal metaphor'?; 10.2 Mutationists v. selectionists: a protracted debate; 10.3 The structure of morphospace; 10.4 Creation and destruction; Part XI. Ontogeny and Phylogeny Re-Visited: 11.1 Mapping the two hierarchies; 11.2 From two hierarchies to six; 11.3 An important general pattern; 11.4 Larval forms and complex life histories; 11.5 Phenotypic complexity and evolutionary 'explosions'; Part XII. Prospect: Expanding the Synthesis: 12.1 Neither boredom nor heresy; 12.2 Completing the evolutionary circle; 12.3 The main themes of Evolutionary Developmental Biology; 12.4 Paths into the future; References; Index.