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 3 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.
List of Illustrations xvii
List of Tables xxiii
List of Boxes xxv
PART 1 Early Problems, Early Solutions 1
1 Speciation, Adaptive Radiation, and Evolution 3
2 Daphne Finches: A Question of Size 17
3 Heritable Variation 41
4 Natural Selection and Evolution 55
5 Breeding Ecology and Fitness 77
PART 2 Developing a Long-Term Perspective 101
6 A Potential Competitor Arrives on Daphne 103
7 Competition and Character Displacement 122
8 Hybridization 138
9 Variation and Introgression 166
PART 3 Hybridization and Speciation 181
10 Long-Term Trends in Hybridization 183
11 Long- Term Trends in Natural Selection 205
12 Speciation 229
13 Speciation by Introgressive Hybridization 245
PART 4 Syntheses 269
14 The Future of Finches on Daphne 271
15 Themes and Issues 287
16 Generalization 300
17 Epilogue 310
Subject Index 389
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.
"For the Grants, Daphne Major has been a magic well. With their four decades of work on the island, they've made it a magnificent microcosm, a model of life on Earth."
– Jonathan Weiner, New York Times
"For the Grants, evolution isn't a theoretical abstraction. It's gritty and real and immediate and stunningly fast [...] Most of all, the book is an affirmation of the importance of long-term fieldwork as a way of capturing the true dynamism of evolution."
– Joel Achenbach, Princeton Alumni Weekly
"The study described here is truly exceptional. Peter and Rosemary Grant [...] have devoted their careers to the study of the group of birds known as Darwin's finches on the Galapagos archipelago, one of the most isolated and inhospitable places on Earth. But the payoff is that their research furnishes some of the most compelling evidence for natural selection and the origin of species [...] The Grants' achievement is monumental."
– Tim Birkhead, Times Higher Education
"Reading this book is like having an engaging conversation with two of the most prominent and charming field biologists of our time. Come listen to their singular adventure, unprecedented insight, and eyewitness account of evolution in action. A terrific must-read for all students of biology, from enthusiasts to experts."
– Hopi E. Hoekstra, Harvard University
"This masterful work summarizes four decades of research on Darwin's finches by the Grants and their many students and collaborators. The book provides an eloquent illustration of how our general understanding of evolution is advanced by a rigorous, sustained focus on a handful of species on a single island."
– Joel G. Kingsolver, University of North Carolina, Chapel Hill
"A captivating synthesis of arguably the most important research program in evolutionary biology in the last half century. From classic work on Darwin's finches decades ago to groundbreaking new discoveries, it's all here. A must-read for any student of evolution."
– Jonathan Losos, Harvard University
"In this delightful and informative book, Peter and Rosemary Grant bring readers along on their four-decade voyage of discovery into the lives of Darwin's finches in the Galápagos archipelago. This is a book about evolutionary change and the origin of new species. The Grants' story – about themselves, natural history and scientific inquiry, and birds and speciation – will inspire anyone with an interest in the natural world."
– Robert E. Ricklefs, University of Missouri, St. Louis
"This magnificent book is about the most successful field study on evolution ever conducted – the Darwin finch project on the island of Daphne Major. There is no other book or team of researchers that tells similar stories with such fine detail and such a clear eye over an equivalent span of time. Defying comparison, 40 Years of Evolution is one for the ages."
– Dolph Schluter, University of British Columbia
"Where were you in 1973? Rosemary and Peter Grant had just started a project that today forms the content of one of the most intriguing books I have ever read. I have to say upfront that this is not an easy read, being quite scientific and technical in parts, however, help can be found in the substantial glossary.
The stars of the book are the Geospiza finch populations, commonly referred to as Darwin’s finches, on Daphne Major with the lead role going to G. fortis, the Medium Ground-finch. The book takes you on our star’s evolutionary journey from heritability to speciation, via natural selection, competition and hybridisation. The chapter on speciation is particularly good and demonstrates this key function of evolution happening right before your eyes.
But what of the future? Well the book covers that too; but I am not about to give the end of the story away. Read it for yourself. You’ll be glad you did!"
– Allan Archer, BTO book reviews, September 2014