Ecological speciation / Patrik Nosil

Incluye bibliografía: páginas 225-270 índice: páginas 271-280

Introduction.. Abbreviations.. Part I: Ecological speciation and its alternatives I What is ecological speciation?.. 1.1. The often-continuous nature of the speciation process.. 1.2. Ecological speciation via divergent natural selection.. 1.3. A brief history of the ecological speciation hypothesis.. 1.4. Alternatives to ecological speciation.. 1.4.1. Models of speciation lacking selection.. 1.4.2. Mutation-order speciation.. 1.5. Other roles for ecology in speciation: population persistence and niche conservatism.. 1.6. Summary.. 2 Predictions and tests of ecological speciation.. 2.1. Comparative approaches (ERG.. 2.1.1. Parallel speciation.. 2.1.2. Parallel speciation via experimental evolution in the lab.. 2.1.3. Parallel speciation in the wild.. 2.1.4. Difficulties with tests of parallel speciation.. 2.1.5. Explicit criteria for parallel speciation.. 2.2. Trait-based approaches ("magic traits".. 2.2.1. "Automatic" magic traits.. 2.2.2. "Classic" magic traits.. 2.2.3. Magic traits in the lab.. 2.2.4. Magic traits: conclusions.. 2.3. Fitness-based approaches (selection = RI.. 2.3.1. Immigrant inviability.. 2.3.2. Ecologically dependent selection against hybrids.. 2.4. Gene-flow-based approaches (isolation-by-adaptation.. 2.4.1. Isolation-by-adaptation: evidence.. 2.4.2. Isolation-by-adaptation at putatively neutral genes: caveats.. 2.4.3. Mosaic hybrid zones, phylogeographic studies, divergence-with-gene-flow models.. 2.5. Phylogenetic shifts method.. 2.6. Inferring causality when testing for ecological speciation.. 2.6.1. Divergence after speciation is complete.. 2.7. Tests and predictions of ecological speciation: conclusions and future directions.. Part II: Components of ecological speciation.. 3 A source of divergent selection.. 3.1. Differences between environments.. 3.1.1. Examples.. 3.1.2. Inferring divergent selection from adaptive landscapes

3.1.3. An alternative to divergent selection: evolution on "holey" adaptive landscapes.. 3.1.4. Linking differences between environments to reproductive isolation.. 3.2. Interactions among populations.. 3.2.1. Competition between closely related species.. 3.2.2. Intraspecific competition within a single population.. 3.2.3. Reinforcement.. 3.2.4. Distinguishing competition from reinforcement.. 3.2.5. Other interactions: mutualisms, tri-trophic interactions, and coevolution.. 3.2.6. Linking interactions between populations to reproductive isolation.. 3.3. The functional morphology and biomechanics of divergent selection.. 3.4. Environmentally dependent sexual selection.. 3.4.1. Divergent sexual selection through sensory drive.. 3.4.2. Examples of divergent sexual selection via sensory drive.. 3.4.3. A note on multimodal mating signals.. 3.4.4. Divergent sexual selection: conclusions and remaining questions.. 3.5. Interactions between the different sources of divergent selection.. 3.6. Sources of divergent selection: conclusions.. 4 A form of reproductive isolation.. 4.1. The different forms of reproductive isolation.. 4.1.1. Divergent habitat preferences and developmental schedules.. 4.1.2. Immigrant inviability.. 4.1.3. Divergent mating and pollinator preferences.. 4.1.4. Postmating, prezygotic incompatibility.. 4.1.5. Intrinsic hybrid incompatibilities.. 4.1.6. Ecologically dependent selection against hybrids.. 4.1.7. Sexual selection against hybrids.. 4.1.8. Forms of reproductive isolation: conclusions.. 4.2. How common are different forms of reproductive isolation during ecological speciation?.. 4.3. For a given point in the speciation process, do multiple reproductive barriers act, and what are their relative contributions to total reproductive isolation?.. 4.4. Across the ecological speciation process, at what point do different barriers evolve?.. 4.5. Forms of reproductive isolation: conclusions and future directions

5 A genetic mechanism to link selection to reproductive isolation.. 5.1. Genetics of ecological speciation: the theory of divergence hitchhiking.. 5.2. Linking selection to reproductive isolation via pleiotropy.. 5.3. Linking selection to reproductive isolation via linkage disequilibrium.. 5.3.1. Tight physical linkage.. 5.3.2. Linkage disequilibrium and factors that reduce recombination: theory.. 5.3.3. Linkage disequilibrium and factors that reduce recombination: data.. 5.3.4. One-allele assortative mating mechanisms.. 5.3.5. Strong selection.. 5.3.6. Genetics mechanisms linking selection to reproductive isolation: conclusions.. 5.4. Genetic constraints on ecological speciation.. 5.5. The individual genetic basis of traits under selection and traits conferring reproductive isolation.. 5.5.1. Theoretical relevance of number of loci under selection for speciation.. 5.5.2. Genetic basis of adaptive divergence and reproductive isolation during ecological speciation.. 5.5.3. Opposing genetic dominance as a form of reproductive isolation.. 5.6. Ecological speciation genes.. 5.6.1. Genes that affect reproductive isolation today.. 5.6.2. Timing of divergence.. 5.6.3. Speciation effect sizes.. 5.6.4. Ecological speciation genes: conclusions.. 5.7. Genetic mechanisms: conclusions and future directions.. Part III: Unresolved issues.. 6 The geography of ecological speciation.. 6.1. Geographic views and definitions of speciation.. 6.1.1. Spatial, demie non-spatial, and spatial population genetic views.. 6.1.2. Allopatric ecological speciation.. 6.2. Non-allopatric speciation: geographic contact constrains divergence.. 6.2.1. The balance between selection and gene flow: theory.. 6.2.2. The balance between selection and gene flow: data.. 6.3. Non-allopatric speciation: geographic contact promotes divergence.. 6.3.1. The "cascade reinforcement" hypothesis.. 6.3.2. Geographic contact and adaptive spread of chromosomal inversion

6.3.3. Hybridization as a source of novelty: the "hybrid swarm" theory of adaptive radiation.. 6.4. The balance between constraining and diversifying effects of gene flow.. 6.5. Multiple geographic modes of divergence.. 6.6. Two problems with detecting divergence in the face of gene flow.. 6.7. Detecting divergence in the face of gene flow: comparative geographic approaches.. 6.8. Detecting divergence in the face of gene flow: coalescent approaches.. 6.8.1. Reliably detecting that gene flow occurred at some point in time.. 6.8.2. The timing of gene flow in relation to the evolution of reproductive isolation.. 6.9. Detecting divergence with gene flow: genomic approaches.. 6.10. The spatial context of selection: discrete patches versus continuous gradients.. 6.11. The spatial scale of speciation.. 6.12. Geography of ecological speciation: conclusions.. 7 The genomics of ecological speciation.. 7.1. Heterogeneous genomic divergence.. 7.2. The metaphor of genomic islands of divergence.. 7.2.1. Experimental evidence for "genomic continents" of speciation.. 7.2.2. An integrated view of the size and the number of divergent gene regions.. 7.2.3. The growth of genomic regions of divergence.. 7.3. Selective sweeps and adaptation from standing variation versus new mutations.. 7.4. Gene expression and ecological speciation.. 7.4.1. Gene expression and adaptive genetic divergence.. 7.4.2. Gene expression and reproductive isolation.. 7.4.3. Gene expression and ecological speciation: conclusions.. 7.5. The genomics of ecological speciation: conclusions and future directions.. 8 The speciation continuum: what factors affect how far speciation proceeds?.. 8.1. The speciation continuum.. 8.2. The stability of partial reproductive isolation.. 8.2.1. The "stuck partway" view of speciation.. 8.2.2. The "feedback loop" view of speciation.. 8.2.3. Reconciliation of views: time-dependence of stability and the "speciation slowdown"

8.3. Non-selective explanations for how far speciation proceeds.. 8.4. Ecological explanations for how far speciation proceeds.. 8.4.1. Dimensionality of ecological shifts.. 8.5. Multifarious versus stronger selection: theory.. 8.5.1. Contributions to total selection.. 8.5.2. Per-trait selection coefficients and correlated evolutionary response.. 8.5.3. Differential importance at different stages of the speciation process.. 8.6. Multifarious versus stronger selection: phenotypic tests.. 8.6.1. Phenotypic support for the stronger selection hypothesis.. 8.6.2. Phenotypic support for the multifarious selection hypothesis.. 8.6.3. Problems with phenotypic tests.. 8.7. Multifarious versus stronger selection: genomic tests.. 8.7.1. Genomic support for the stronger and multifarious selection hypotheses.. 8.7.2. Hypothetical experimental genomic tests.. 8.8. Other factors affecting the speciation continuum.. 8.8.1. Temporal stability of divergent selection.. 8.8.2. Alternative outcomes to speciation: sexual dimorphism and phenotypic plasticity.. 8.9. The speciation continuum: conclusions and future directions.. 9 Conclusions and future directions.. 9.1. What we know about ecological speciation.. 9.2. Future work: 25 unresolved issues in ecological speciation.. 9.3. Competing hypotheses deserving further work.. 9.4. Issues warranting further work that were not covered in detail.. 9.4.1. Tempo and rate of ecological speciation.. 9.4.2. How common is ecological speciation?.. 9.4.3. Joint action and interactions between speciation models.. 9.4.4. Consequences of ecological speciation.. 9.5. Final conclusion.. References.. Index

The origin of biological diversity, via the formation of new species, can be inextricably linked to adaptation to the ecological environment. Specifically, ecological processes are central to the formation of new species when barriers to gene flow (reproductive isolation) evolve between populations as a result of ecologically-based divergent natural selection. This process of 'ecological speciation' has seen a large body of particularly focused research in the last 10-15 years, and a review and synthesis of the theoretical and empirical literature is now timely. The book begins by clarifying what ecological speciation is, its alternatives, and the predictions that can be used to test for it. It then reviews the three components of ecological speciation and discusses the geography and genomic basis of the process. A final chapter highlights future research directions, describing the approaches and experiments which might be used to conduct that future work. The ecological and genetic literature is integrated throughout the text with the goal of shedding new insight into the speciation process, particularly when the empirical data is then further integrated with theory. eng