Cover image for 40 years of evolution : Darwin's Finches on Daphne Major Island
40 years of evolution : Darwin's Finches on Daphne Major Island
Grant, Peter R., 1936-
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Publication Information:
Princeton ; Oxford : Princeton University Press, [2014]

Physical Description:
xxxii, 400 pages : illustrations (some color), maps (some color) ; 25 cm
Speciation, adaptive radiation, and evolution -- Daphne finches : a question of size -- Heritable variation -- Natural selection and evolution -- Breeding ecology and fitness -- A potential competitor arrives on Daphne -- Competition and character displacement -- Hybridization -- Variation and introgression -- Long-term trends in hybridization -- Long-term trends in natural selection -- Speciation -- Speciation by introgressive hybridization -- The future of finches on Daphne -- Themes and issues -- Generalization -- Epilogue -- 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.
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QL696.P246 G7324 2014 Adult Non-Fiction Non-Fiction Area

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Renowned evolutionary biologists Peter and Rosemary Grant have produced landmark studies of the Galápagos finches first made famous by Charles Darwin. In How and Why Species Multiply , they offered a complete evolutionary history of Darwin's finches since their origin almost three million years ago. Now, in their richly illustrated new book, 40 Years of Evolution , the authors turn their attention to events taking place on a contemporary scale. By continuously tracking finch populations over a period of four decades, they uncover the causes and consequences of significant events leading to evolutionary changes in species.

The authors used a vast and unparalleled range of ecological, behavioral, and genetic data--including song recordings, DNA analyses, and feeding and breeding behavior--to measure changes in finch populations on the small island of Daphne Major in the Galápagos archipelago. They find that natural selection happens repeatedly, that finches hybridize and exchange genes rarely, and that they compete for scarce food in times of drought, with the remarkable result that the finch populations today differ significantly in average beak size and shape from those of forty years ago. The authors' most spectacular discovery is the initiation and establishment of a new lineage that now behaves as a new species, differing from others in size, song, and other characteristics. The authors emphasize the immeasurable value of continuous long-term studies of natural populations and of critical opportunities for detecting and understanding rare but significant events.

By following the fates of finches for several generations, 40 Years of Evolution offers unparalleled insights into ecological and evolutionary changes in natural environments.

Author Notes

Peter R. Grant and B. Rosemary Grant are both emeritus professors in the Department of Ecology and Evolutionary Biology at Princeton University. They are the coauthors of How and Why Species Multiply and coeditors of In Search of the Causes of Evolution (both Princeton).

Reviews 1

Choice Review

When Darwin visited the Galápagos Islands in the 1830s, he collected birds that became known as "Darwin's finches." But he did not really conduct in-depth studies, and preliminary efforts to provide specimen localities and identifications were ultimately made by British Museum staff long after his return. This volume is a masterpiece of evolutionary studies on some of the finches from one of the islands, Daphne Major. Peter Grant and Rosemary Grant (both, emer., Princeton Univ.) spent 40 years studying finches on Daphne Major and to a lesser extent on some of the other islands. By detailed analysis of the species through extensive trapping, they uncovered various events that led to evolutionary changes. They examined speciation processes involving size changes, breeding ecology, fitness factors, competitive interactions, hybridization, introgression, and more. The detailed text includes many photographs of the birds, charts showing anatomical features and graphs of changes, and 30-plus pages of references. This volume not only provides detailed evidence of the evolution of a specific group of animals, but also offers an overall perspective on how and in what ways bird species have changed in this rather isolated locality. The text serves as a lab experiment providing evidence of change through time. --David Bardack, University of Illinois at Chicago

Table of Contents

List of Illustrationsp. xvii
List of Tablesp. xxiii
List of Boxesp. xxv
Prefacep. xxvii
Part 1 Early Problems, Early Solutionsp. 1
1 Speciation, Adaptive Radiation, and Evolutionp. 3
Introductionp. 3
Adaptive Radiation of Darwin's Finchesp. 4
Species and Speciationp. 9
Daphnep. 10
Evolution Observedp. 12
Chapters of the Bookp. 15
Summaryp. 16
2 Daphne Finches: A Question of Sizep. 17
Introductionp. 17
Testing the Hypothesisp. 21
Availability Of Foodp. 22
Diets of G. Fortis and G. Fuliginosap. 22
Differences in Seed Supplyp. 27
G. Fuliginosa On Los Hermanosp. 28
Association between Beak Size and Dietp. 30
Adaptive Landscapesp. 30
Can G. scandens Be Ignored?p. 35
Why Is G. fuliginosa Absent?p. 37
Discussionp. 39
Summaryp. 39
3 Heritable Variationp. 41
Introductionp. 41
Estimating Heritable Variationp. 43
Heritable Variationp. 44
Potential Biasesp. 46
Extra-Pair Paternityp. 46
Misidentified Paternityp. 47
Maternal Effectsp. 47
Genotype X Environment Correlationp. 48
Conclusions on Biasp. 49
Heritabilities: A Comparison of Speciesp. 49
Summaryp. 53
4 Natural Selection and Evolutionp. 55
Introductionp. 55
Expectationsp. 56
Natural Selectionp. 57
Causes of Selective Mortalityp. 59
The Targets of Selectionp. 61
Evolution in Response to Selectionp. 62
Selection Occurs Repeatedlyp. 63
Selection Oscillates in Directionp. 67
Evolutionary Responsep. 73
Selection in Opposite Directionsp. 74
Conclusionsp. 75
Summaryp. 75
5 Breeding Ecology and Fitnessp. 77
Introductionp. 77
Basic Breeding Biologyp. 78
Annual Variation in Reproduction in 81 Relation to Rainp. 81
Predicting Reproductive Successp. 87
The Cohorts of 1975p. 87
Four Later Cohortsp. 89
The Contribution of Morphology to Fitnessp. 90
The Contribution of Offspring to Parental Fitnessp. 93
Longevityp. 93
Inbreedingp. 96
Variation in Fitnessp. 97
Discussionp. 99
Summaryp. 100
Part 2 Developing a Long-Term Perspectivep. 101
6 A Potential Competitor Arrives on Daphnep. 103
Introductionp. 103
Founder Eventp. 105
Causesp. 105
First Few Generationsp. 106
Inbreedingp. 107
Fitness Costs of Inbreedingp. 107
Immigrationp. 108
Selectionp. 109
Genetic Diversityp. 111
Losses and Gains of Allelesp. 112
The Source of Immigrantsp. 112
Nonrandom Colonizationp. 115
Songp. 115
Colonization Successp. 117
Summaryp. 119
7 Competition and Character Displacementp. 122
Introductionp. 122
Competition and Diet Overlapp. 123
Effects of Competition on Survivalp. 123
Character Displacementp. 125
Strength of Selectionp. 128
The Causal Role of G. Magnirostrisp. 129
High impact on food supplyp. 130
Superior feeding efficiency on shared component of the dietp. 130
Parallel decline due to starvationp. 130
Key difference between 1977 and 2004p. 132
Evolution of a Displaced Characterp. 132
G. Fortis and Scandens Comparedp. 133
Some Implicationsp. 134
Summaryp. 136
8 Hybridizationp. 138
Introductionp. 138
Backgroundp. 139
Frequency of Hybridizationp. 141
Causes of Hybridizationp. 141
A Scarcity of Conspecific Matesp. 141
Imprintingp. 143
Song Inheritancep. 143
Perturbation of Imprintingp. 149
G. Magnirostrisp. 153
Fitness Consequences of Hybridizationp. 156
Viabilityp. 156
Fertilityp. 160
Overall Fitnessp. 160
The Mating Pattern of Hybridsp. 163
Conclusionsp. 164
Summaryp. 165
9 Variation and Introgressionp. 166
Introductionp. 166
Morphology of Hybridsp. 169
Effects of Hybridization on Variationp. 169
Comparison of G. Fortis and G. Scandensp. 171
Conspecific Gene Flowp. 174
Hybridization versus Mutationp. 174
Correlationsp. 176
Evolutionary Potentialp. 177
Discussionp. 178
Summaryp. 179
Part 3 Hybridization and Speciationp. 181
10 Long-Term Trends in Hybridizationp. 183
Introductionp. 183
A Question of Identityp. 184
Blurring of Genetic Distinctionsp. 185
Blurring of Morphological Distinctionsp. 188
Morphological Convergencep. 190
Frequencies of Hybridsp. 191
Morphological Variationp. 192
Allometryp. 194
Genetic Convergencep. 196
Two Species or One?p. 199
Plumage and Behaviorp. 201
Discussionp. 201
Summaryp. 204
11 Long-Term Trends in Natural Selectionp. 205
Introductionp. 205
Selectionp. 207
G. Fortisp. 207
G. Scandbnsp. 207
Ecological Causesp. 207
Stabilizing Selectionp. 211
Morphological Trendsp. 211
G. Fortisp. 211
G. Scandensp. 213
G. Magnirostrisp. 216
The Possible Role of Selection on G. Magnirostrisp. 219
Immigrationp. 223
The Cause of the Beak-Size Trendp. 224
Allometry of Meansp. 224
Natural and Artificial Selectionp. 226
Conclusionp. 226
Summaryp. 228
12 Speciationp. 229
Introductionp. 229
Morphological Transformation in Speciationp. 230
Species that Differ in Sizep. 231
Species that Differ in Shapep. 232
Genetic Transformation in Speciationp. 234
Growth after Hatchingp. 236
Rapid Tempo of Speciationp. 238
Interactions in Sympatryp. 239
A Mechanism Producing Song Divergencep. 241
Summaryp. 243
13 Speciation by Introgressive Hybridizationp. 245
Introductionp. 245
A Hybrid Arrives on Daphnep. 247
Descendantsp. 248
Phase 1 The Start of a New Lineagep. 248
The phenotypic uniqueness of 5110p. 250
Phase II Generations 1-3p. 251
Phase III Endogamy and Reproductive Isolationp. 253
Origin of Reproductive Isolationp. 260
Fate of the A Line of Descentp. 260
Success of the Lineage So Farp. 263
Intrinsic Factorsp. 263
Extrinsic Factorsp. 265
Future Prospectsp. 265
Summaryp. 267
Part 4 Synthesesp. 269
14 The Future of Finches on Daphnep. 271
Introductionp. 271
The Past as Context of the Presentp. 272
Merge-and-Diverge Dynamicsp. 275
The Present as a Guide to the Futurep. 275
Global Warming and Galapagosp. 276
Finch Futuresp. 279
Means and Extremesp. 279
G. Fortis, Scandens, and Fuliginosap. 280
G. Magnirostrisp. 280
Hybrid Lineagep. 281
Invasive Plant Species and Diseasep. 283
Genomes for the Futurep. 284
Summaryp. 286
15 Themes and Issuesp. 287
Introductionp. 287
Speciation, Selection, and Hybridizationp. 289
Evolutionp. 289
Ecological Importance of Food: The Daphne Perspectivep. 290
Behavioral Barrier to Interbreedingp. 291
Size and Hybridizationp. 293
Phylogenetic Implications of Hybridizationp. 294
Ephemerality of Speciesp. 294
Predictability and Evolvabilityp. 296
Overviewp. 298
Summaryp. 299
16 Generalizationp. 300
Generalizing When N = 1p. 300
The Small Population Syndromep. 301
The Medium Population Syndromep. 302
Large Islandsp. 303
Beyond Galapagosp. 304
The Specter of Extinction, the Big Unknownp. 306
Summaryp. 308
17 Epiloguep. 310
Reflections on the Value of Long-Term Studiesp. 310
Long-Term Dynamics of a Color Polymorphismp. 311
Rare Events and their Consequencesp. 315
Changes in Perspectivep. 316
Codap. 319
Appendixesp. 321
Appendix 1.1 Daphne Plantsp. 321
Appendix 1.2 Measurements of Finchesp. 323
Appendix 1.3 Other Species of Darwin's Finchesp. 324
Appendix 3.1 Mapping Breeding Locationsp. 324
Appendix 3.2 Annual Changes in Measurementsp. 324
Appendix 5.1 Extra-pair Matingp. 326
Appendix 5.2 Visitors and Predation 327'
Appendix 9.1 Variation and Mortalityp. 328
Appendix 10.1 On the Dangers of Extrapolationp. 331
Appendix 10.2 Plumagep. 331
Appendix 11.1 Samples of Measurements for Selection Analysesp. 332
Appendix 13.1 Identification of Breedersp. 335
Appendix 17.1 Nestling Beak Color Polymorphismp. 335
Abbreviationsp. 341
Glossaryp. 343
Referencesp. 353
Subject Indexp. 389