Note: Intro -- Foreword -- References -- Contents -- Contributors -- 1 Asex and Evolution: A Very Large-Scale Overview -- 1.1 Eukaryote Reproduction and the Meiotic Cycle -- 1.2 Asex Is Often Associated with Polyploidy and Hybridity -- 1.3 Asex Can Have Many Different Immediate Causes -- 1.4 Asex Is the Outcome of a Darwinian Process with Special Properties -- 1.5 Asex Is Almost Always Associated with Some Sex -- 1.6 Most Asexuals Are Genetically Variable -- 1.7 Asexual Lineages Are Comparatively Short-Lived -- 1.8 The Lack of Recombination Gives Asexual Lineages a Long-Term Disadvantage -- 1.9 The Paradox of Asex -- References -- 2 The Evolution of the Problem of Sex -- 2.1 Introduction -- 2.2 Darwin: The Effects of Cross-Fertilization -- 2.2.1 The Early Notebooks: Becoming Interested in the Significance of Sex -- 2.2.2 Sex and Variation -- 2.2.3 Sex Unites a Species -- 2.2.4 Cross-Fertilization: A Law of Nature -- 2.2.5 Sex and Hybrid Vigor -- 2.3 Weismann: The Significance of Sexual Reproduction in the Theory of Natural Selection -- 2.3.1 The Principles of Heredity -- 2.3.2 Heredity, Variability and Sex -- 2.3.3 The Significance of Sex, 1886 -- 2.3.4 The Significance of Sex, 1891 -- 2.3.5 Cyclical and Obligate Parthenogenesis -- 2.4 Fisher: The Contrast Between Sexual and Asexual Reproduction -- 2.4.1 Mendelism and Darwinism -- 2.4.2 The Adaptive Significance of Sex -- 2.4.3 Sex, Time and Levels of Selection -- 2.5 Maynard Smith: The Cost of Sex -- 2.5.1 The Evolutionary Synthesis and Appearing Complexities -- 2.5.2 Group Selection and Sex -- 2.5.3 The Fisher-Muller Model and a Changing Environment -- 2.5.4 The Problem of the Cost of Sex -- 2.5.5 Conceptual Framework -- 2.6 Discussion -- References -- 3 Apomixis: Basics for Non-botanists -- 3.1 Introduction -- 3.2 Vegetative Reproduction in Plants is Not Apomixis. , 3.3 Apomixis Is a Modification of Sexual Reproduction -- 3.4 Types of Apomixis in Flowering Plants -- 3.5 Pseudogamy and Autonomous Endosperm Development -- 3.6 Phenotyping Apomixis -- 3.7 Facultative Apomixis -- 3.8 Causes of Apomixis -- 3.9 Most Apomictic Plants Are Hermaphrodites -- 3.10 Somatic Mutations -- 3.11 The Phylogenetic Distribution of Apomixis in the Flowering Plants -- 3.12 Constraints on the Evolution of Apomixis in Flowering Plants -- 3.13 Ancient Apomicts in Flowering Plants -- 3.14 Further Reading -- 3.15 Glossary -- References -- 4 Cytology of Asexual Animals -- 4.1 The Importance of Cytology -- 4.2 Cytological Mechanisms of Animal Parthenogenesis -- 4.2.1 Automictic Parthenogenesis -- 4.2.1.1 Gamete Duplication -- 4.2.1.2 Terminal Fusion -- 4.2.1.3 Central Fusion -- 4.2.1.4 The First Polar Nucleus Fuses with the Nucleus of the Secondary Oocyte -- 4.2.1.5 Gonoid Thelytoky -- 4.2.1.6 Premeiotic Doubling -- 4.2.2 Apomictic Parthenogenesis -- 4.3 Evolutionary Consequences -- 4.4 Polyploidy in Association with Parthenogenesis -- 4.5 Conclusions -- References -- 5 A Graphical Approach to Lineage Selection Between Clonals and Sexuals -- 5.1 Introduction -- 5.2 Costs and Benefits of Sexual vs Clonal Reproduction -- 5.2.1 Short-Term Costs of Sexual Reproduction -- 5.2.2 Long-Term Costs of Clonal Reproduction -- 5.3 Fundamental Benefits to Sex -- 5.3.1 Equilibrium Mutational Load in Clonal Lineages -- 5.3.2 Contrasting Equilibrium Mutational Load in Sexual and Clonal Lineages -- 5.3.3 A Graphical Depiction of Background-Trapping and the Accumulation of Favourable and Harmful Mutations -- 5.4 Clonal vs Sexual Lineages -- 5.5 Conclusions -- References -- 6 Geographical Parthenogenesis: General Purpose Genotypes and Frozen Niche Variation -- 6.1 Introduction -- 6.1.1 Adaptation at the Margins -- 6.2 General Purpose Genotype (GPG). , 6.2.1 Elevated Ploidy and Hybridity -- 6.2.2 Evidence for General Purpose Genotypes -- 6.3 Frozen Niche-Variation (FNV) -- 6.3.1 Evidence for Frozen Niche Variation -- 6.4 Evolution of Generalist Versus Specialist Clones -- 6.4.1 GPG and FNV Are Not Mutually Exclusive -- 6.5 Conclusions -- References -- 7 Sex and the Red Queen -- 7.1 Sex and the Red Queen Introduction -- 7.2 Assumptions and Predictions of the Model -- 7.2.1 Population Genetics -- 7.2.2 Infection Dynamics -- 7.3 Does It Work? -- 7.3.1 Geographical Distribution of Sex and Outcrossing -- 7.3.2 Frequency of Sex vs Frequency of Infection -- 7.3.3 Susceptibility to Infection -- 7.3.4 Rare Advantage -- 7.3.5 Parasitic Tracking of Common Host Genotypes -- 7.3.6 Parasite Local Adaptation -- 7.3.7 Molecular Evolution in Disease Resistance Loci -- 7.4 Pluralism -- 7.4.1 The Red Queen and Pluralism -- 7.4.2 Empirical Tests -- 7.5 Conclusions -- References -- 8 Geographical Parthenogenesis: Opportunities for Asexuality -- 8.1 Introduction -- 8.2 The Main Current Hypotheses -- 8.3 The Connection of Polyploidy, Hybridization and Asexuality -- 8.4 Hybridization and Polyploidy, and the Cost of Origins of Asexuality -- 8.5 Climatic Changes as Opportunities for Origins and Dispersal of Asexuality -- 8.6 Case Studies in Ranunculus -- 8.7 Suggestions for Future Research -- 8.8 Glossary -- References -- 9 The Elusive Clone In Search of Its True Nature and Identity -- 9.1 Box 9.1: Definitions of Sex and Asex -- 9.1 What Are Clones? -- 9.2 A Brief History of Clonal Concepts -- 9.3 Germline Versus Soma: The Weismannian Doctrine Revisited -- 9.4 Clonal Concepts -- 9.5 Box 9.2: Brief Description of Extant Clonal Concepts -- 9.5 Validity of the Clonal Concepts -- 9.6 Conclusions -- References -- 10 Asexual Speciation -- 10.1 The Importance of Asexual Species. , 10.2 General Theory of Speciation and Species in Asexuals -- 10.3 Criteria for Assigning Individuals to Species -- 10.3.1 The 4X Rule -- 10.3.2 Analysis of Branching Rates -- 10.4 Application to Bdelloid Rotifers -- 10.5 Application to Oribatid Mites -- 10.6 Predictions About Relative Speciation Rates in Sexuals and Parthenogens -- 10.7 Conclusions -- References -- 11 Darwinulid Ostracods: Ancient Asexual Scandals or Scandalous Gossip? -- 11.1 Introduction -- 11.2 Box 11.1 Ostracoda -- 11.2 Ostracods in General -- 11.2 Ostracod Diversity -- 11.2 Reproductive Modes in Ostracods -- 11.2 Ecology of Darwinulidae -- 11.2 Life History of Darwinulidae -- 11.2 Demonstrating the Status of Long-Lived Asexuals -- 11.2.1 Recent Males -- 11.2.2 Fossil Males -- 11.2.3 Genetic Signatures of Ancient Asexuality: The Meselson-White Effect -- 11.2.4 Genomics: Transposons -- 11.2.5 Chromosomal Evidence: Aneuploidy -- 11.2.6 Ancient Asexual Status for Darwinulid Ostracods? -- 11.3 Ecological Strategies of Darwinulid Ostracods -- 11.3.1 GPG Versus FNV -- 11.3.2 Parasites or No Parasites? -- 11.3.3 Marginal Habitats and Long-Term Asexuality -- 11.3.4 Reduced Mutation Rates -- 11.3.5 Brood Selection or Enhanced Fecundity? -- 11.4 How Darwinulids Could Have Survived Without Sex for Millions of Years -- 11.5 What Remains to be Discovered -- References -- 12 Parthenogenesis in Oribatid Mites (Acari, Oribatida): Evolution Without Sex -- 12.1 General Biological Aspects of Oribatid Mites -- 12.1.1 Overview -- 12.1.2 Geological Age -- 12.1.3 Population Density -- 12.1.4 Niche Differentiation and Feeding Biology -- 12.1.5 Functioning -- 12.2 Reproductive and Developmental Biology -- 12.2.1 General Aspects -- 12.2.2 Female System and Reproductive Strategies -- 12.2.3 Parthenogenesis -- 12.2.4 Endosymbiotic Bacteria -- 12.3 Phylogeny of Parthenogenetic Lineages. , 12.3.1 General Phylogeny -- 12.3.2 Radiation of Parthenogenetic Lineages -- 12.4 Glossary -- References -- 13 Bdelloid Rotifers: Progress in Understanding the Success of an Evolutionary Scandal -- 13.1 Introduction -- 13.2 Evidence of Long-Term Asexuality in Bdelloidea -- 13.3 Environmental Adaptations in Bdelloidea -- 13.4 Anhydrobiosis -- 13.5 Ionizing Radiation and Desiccation -- 13.6 Genome Structure -- 13.7 Synthesis -- References -- 14 Sex Loss in Monogonont Rotifers -- 14.1 Introduction -- 14.2 The Monogonont Life Cycle -- 14.3 The Timing of Sex -- 14.4 The Cost of Sex in Cyclically Parthenogenetic Life Cycles -- 14.5 Mechanisms of Sex Loss in Monogononts -- 14.6 Selection for Sex Loss -- 14.7 Dormancy and Sex -- References -- 15 Cyclical Parthenogenesis in Daphnia : Sexual Versus Asexual Reproduction -- 15.1 Introduction -- 15.2 Cyclical Parthenogenesis and Its Effect on the Genetic Structure of Daphnia Populations -- 15.3 Reasons to Maintain Sexual Reproduction in Daphnia -- 15.3.1 Local Genetic Adaptation -- 15.3.2 Red Queen Dynamics -- 15.3.3 Deleterious Mutations -- 15.4 Evolution to Asexuality in Daphnia and Other Cladocerans -- 15.5 Why Switch to Asexual Reproduction When You Can Be a Cyclical Parthenogen? -- 15.5.1 Clonal Erosion and Inbreeding -- 15.5.2 Food Limitations and Time Stress -- 15.5.3 Genetic Slippage and Time Stress -- 15.5.4 Polyploidy and Hybrid Vigour -- 15.5.5 Contagious Asexuality: Selfish or Not? -- 15.6 Conclusions -- References -- 16 Metasexual Stick Insects: Model Pathways to Losing Sex and Bringing It Back -- 16.1 Introduction -- 16.1.1 Asexuals and Sexuals -- 16.1.2 Parthenogenesis and Polyploidy -- 16.2 Sexual and Asexual Stick Insects -- 16.2.1 Bacillus (Latreille) -- 16.2.2 Leptynia Pantel and Pijnackeria Scali -- 16.3 Centrosome Dynamics and -Tubulin(s) in Stick Insects. , 16.4 Conclusions Are Stick Insects True Asexuals?.