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Index
Cover Page
Title Page
Copyright Page
Dedication Page
Contents
List of Illustrations
List of Tables
List of Boxes
Preface
Part 1: Early Problems, Early Solutions
1 Speciation, Adaptive Radiation, and Evolution
Introduction
Adaptive Radiation of Darwin’s Finches
Species and Speciation
Daphne
Evolution Observed
Chapters of the Book
Summary
2 Daphne Finches: A Question of Size
Introduction
Testing the Hypothesis
Availability of Food
Diets of G. Fortis and G. Fuliginosa
Differences in Seed Supply
G. Fuliginosa on Los Hermanos
Association between Beak Size and Diet
Adaptive Landscapes
Can G. scandens Be Ignored?
Why Is G. fuliginosa Absent?
Discussion
Summary
3 Heritable Variation
Introduction
Estimating Heritable Variation
Heritable Variation
Potential Biases
Extra-Pair Paternity
Misidentified Paternity
Maternal Effects
Genotype × Environment Correlation
Conclusions on Bias
Heritabilities: A Comparison of Species
Summary
4 Natural Selection and Evolution
Introduction
Expectations
Natural Selection
Causes of Selective Mortality
The Targets of Selection
Evolution in Response to Selection
Selection Occurs Repeatedly
Selection Oscillates in Direction
Evolutionary Response
Selection in Opposite Directions
Conclusions
Summary
5 Breeding Ecology and Fitness
Introduction
Basic Breeding Biology
Annual Variation in Reproduction in Relation to Rain
Predicting Reproductive Success
The Cohorts of 1975
Four Later Cohorts
The Contribution of Morphology to Fitness
The Contribution of Offspring to Parental Fitness
Longevity
Inbreeding
Variation in Fitness
Discussion
Summary
Part 2: Developing a Long-Term Perspective
6 A Potential Competitor Arrives on Daphne
Introduction
Founder Event
Causes
First Few Generations
Inbreeding
Fitness Costs of Inbreeding
Immigration
Selection
Genetic Diversity
Losses and Gains of Alleles
The Source of Immigrants
Nonrandom Colonization
Song
Colonization Success
Summary
7 Competition and Character Displacement
Introduction
Competition and Diet Overlap
Effects of Competition on Survival
Character Displacement
Strength of Selection
The Causal Role of G. Magnirostris
High impact on food supply
Superior feeding efficiency on shared component of the diet
Parallel decline due to starvation
Key difference between 1977 and 2004
Evolution of a Displaced Character
G. Fortis and Scandens Compared
Some Implications
Summary
8 Hybridization
Introduction
Background
Frequency of Hybridization
Causes of Hybridization
A Scarcity of Conspecific Mates
Imprinting
Song Inheritance
Perturbation of Imprinting
G. Magnirostris
Fitness Consequences of Hybridization
Viability
Fertility
Overall Fitness
The Mating Pattern of Hybrids
Conclusions
Summary
9 Variation and Introgression
Introduction
Morphology of Hybrids
Effects of Hybridization on Variation
Comparison of G. Fortis and G. Scandens
Conspecific Gene Flow
Hybridization versus Mutation
Correlations
Evolutionary Potential
Discussion
Summary
Part 3: Hybridization and Speciation
10 Long-Term Trends in Hybridization
Introduction
A Question of Identity
Blurring of Genetic Distinctions
Blurring of Morphological Distinctions
Morphological Convergence
Frequencies of Hybrids
Morphological Variation
Allometry
Genetic Convergence
Two Species or One?
Plumage and Behavior
Discussion
Summary
11 Long-Term Trends in Natural Selection
Introduction
Selection
G. Fortis
G. Scandens
Ecological Causes
Stabilizing Selection
Morphological Trends
G. Fortis
G. Scandens
G. Magnirostris
The Possible Role of Selection on G. Magnirostris
Immigration
The Cause of the Beak-Size Trend
Allometry of Means
Natural and Artificial Selection
Conclusion
Summary
12 Speciation
Introduction
Morphological Transformation in Speciation
Species that Differ in Size
Species that Differ in Shape
Genetic Transformation in Speciation
Growth after Hatching
Rapid Tempo of Speciation
Interactions in Sympatry
A Mechanism Producing Song Divergence
Summary
13 Speciation by Introgressive Hybridization
Introduction
A Hybrid Arrives on Daphne
Descendants
Phase 1: The Start of a New Lineage
The phenotypic uniqueness of 5110
Phase II: Generations 1–3
Phase III: Endogamy and Reproductive Isolation
Origin of Reproductive Isolation
Fate of the A Line of Descent
Success of the Lineage So Far
Intrinsic Factors
Extrinsic Factors
Future Prospects
Summary
Part 4: Syntheses
14 The Future of Finches on Daphne
Introduction
The Past as Context of the Present
Merge-and-Diverge Dynamics
The Present as a Guide to the Future
Global Warming and Galápagos
Finch Futures
Means and Extremes
G. Fortis, Scandens, and Fuliginosa
G. Magnirostris
Hybrid Lineage
Invasive Plant Species and Disease
Genomes for the Future
Summary
15 Themes and Issues
Introduction
Speciation, Selection, and Hybridization
Evolution
Ecological Importance of Food: The Daphne Perspective
Behavioral Barrier to Interbreeding
Size and Hybridization
Phylogenetic Implications of Hybridization
Ephemerality of Species
Predictability and Evolvability
Overview
Summary
16 Generalization
Generalizing When N = 1
The Small Population Syndrome
The Medium Population Syndrome
Large Islands
Beyond Galápagos
The Specter of Extinction, The Big Unknown
Summary
17 Epilogue
Reflections on the Value of Long-Term Studies
Long-Term Dynamics of a Color Polymorphism
Rare Events and Their Consequences
Changes in Perspective
Coda
Appendixes
Appendix 1.1 Daphne Plants
Appendix 1.2 Measurements of Finches
Appendix 1.3 Other Species of Darwin’s Finches
Appendix 3.1 Mapping Breeding Locations
Appendix 3.2 Annual Changes in Measurements
Appendix 5.1 Extra-pair Mating
Appendix 5.2 Visitors and Predation
Appendix 9.1 Variation and Mortality
Appendix 10.1 On the Dangers of Extrapolation
Appendix 10.2 Plumage
Appendix 11.1 Samples of Measurements for Selection Analyses
Appendix 13.1 Identification of Breeders
Appendix 17.1 Nestling Beak Color Polymorphism
Abbreviations
Glossary
References
Subject Index
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