How and Why Species Multiply: The Radiation of Darwin's Finches

by Peter R. Grant, B. Rosemary Grant

Overview

Charles Darwin's experiences in the Galápagos Islands in 1835 helped to guide his thoughts toward a revolutionary theory: that species were not fixed but diversified from their ancestors over many generations, and that the driving mechanism of evolutionary change was natural selection. In this concise, accessible book, Peter and Rosemary Grant explain what we have learned about the origin and evolution of new species through the study of the finches made famous by that great scientist: Darwin's finches.

Drawing upon their unique observations of finch evolution over a thirty-four-year period, the Grants trace the evolutionary history of fourteen different species from a shared ancestor three million years ago. They show how repeated cycles of speciation involved adaptive change through natural selection on beak size and shape, and divergence in songs. They explain other factors that drive finch evolution, including geographical isolation, which has kept the Galápagos relatively free of competitors and predators; climate change and an increase in the number of islands over the last three million years, which enhanced opportunities for speciation; and flexibility in the early learning of feeding skills, which helped species to exploit new food resources. Throughout, the Grants show how the laboratory tools of developmental biology and molecular genetics can be combined with observations and experiments on birds in the field to gain deeper insights into why the world is so biologically rich and diverse.

Written by two preeminent evolutionary biologists, How and Why Species Multiply helps to answer fundamental questions about evolution—in the Galápagos and throughout the world.

Product Details

ISBN-13:	9780691149998
Publisher:	Princeton University Press
Publication date:	05/29/2011
Series:	Princeton Series in Evolutionary Biology
Pages:	272
Product dimensions:	6.00(w) x 9.20(h) x 0.70(d)

About the Author

Peter R. Grant and B. Rosemary Grant are professors emeriti at Princeton University. In recognition of their decades of work studying the ecology, behavior, genetics, and evolution of Darwin's finches, they were awarded the 2005 Balzan Prize and the 2009 Kyoto Prize.

Table of Contents

List of Illustrations xi

List of Tables xv

Preface xvii

CHAPTER ONE: The Biodiversity Problem and Darwin's Finches 1

Biodiversity 1

The Choice of Organisms 2

Darwin's Finches 3

Diversity of Darwin's Finch Species 5

Species and Populations 8

Overview of the Book 11

CHAPTER TWO: Origins and History 13

Introduction 13

Phylogeny 14

Ancestors 16

The Time of Arrival 16

Colonization 17

The Ecological Theater 18

A Change of Scenery 21

The Evolutionary Play 22

Recent History 22

Summary 25

CHAPTER THREE: Modes of Speciation 26

The Formation of New Species 26

Two Groups from One 27

Divergence in Allopatry 28

Coexistence in Sympatry 29

Sympatric Speciation 30

Parapatric Speciation 31

Testing the Models 33

Summary 33

CHAPTER FOUR: Colonization of an Island 35

Speciation: The Initial Split 35

Establishment of a New Population 35

Founder Effects: Expectations from Theory 36

A Colonization Event 38

Inbreeding 39

Recurrent Immigration 39

An Alternative Phenology of Founder Effects 42

Conclusion 42

Species Elsewhere 44

Summary 45

CHAPTER FIVE: Natural Selection, Adaptation, and Evolution 46

Adaptation 46

Beak Sizes and Diets 47

Adaptive Evolution When the Environment Changes 50

Natural Selection 52

Evolution 54

Oscillating Directional Selection 55

Extrapolating from Short to Long Term 58

The Sources of Variation 58

How Beaks Are Formed 59

Depth and Width 59

Length 62

Summary 63

CHAPTER SIX: Ecological Interactions 65

Introduction 65

Competition 66

Patterns of Coexistence 66

Diets Inferred from Beaks 67

Interpreting the Patterns 67

Character Displacement and Release 68

Character Displacement Observed 68

The Competitive Role of G. Magnirostris 69

Selection under Contrasting Conditions 73

Evolution of Character Displacement 73

Summary 75

CHAPTER SEVEN: Reproductive Isolation 76

Pre-mating Barrier to Interbreeding 76

Factors Involved in the Discrimination between Species 76

Beaks 77

Song 77

Learning 79

Song Differences between Species 80

Song Divergence in Allopatry 81

Adaptation to Habitat 83

Change of Songs as a Consequence of
Morphological Divergence 84

The Role of Chance 86

Simulating Secondary Contact 88

Summary 91

CHAPTER EIGHT: Hybridization 92

Introduction 92

Hybridization 92

Why Hybridization Occurs 93

When Hybridization Does Not Occur 96

Hybrid Fitness 97

Introgression on Daphne Major 100

Introgression in the Archipelago 103

Reinforcement 103

Reproductive Character Displacement 105

Evolutionary Significance of Introgression 106

Summary 107

CHAPTER NINE: Species and Speciation 108

Introduction 108

From Process to Product:What Is a Species? 109

A Working Definition 110

How Many Species of Darwin's Finches? 111

Certhidea olivacea: One Species or Two? 112

Geospiza difficilis: One Species or Three? 113

From Product Back to Process 114

Fission and Fusion 116

Summary 119

CHAPTER TEN: Reconstructing the Radiation of Darwin's Finches 120

Introduction 120

The Shape of the Radiation 121

Speciation and Extinction 123

Speciation 125

Extinction 126

Implications for Phylogeny 127

Adaptive Landscape 128

A Pattern of Ecological Segregation 133

Specialization 134

The Buildup of Complex Communities 134

Summary 135

CHAPTER ELEVEN: Facilitators of Adaptive Radiation 137

Introduction 137

Environmental Opportunity 138

Geographical Suitability 139

Ecological Opportunity 140

High Diversification Potential 142

Behavioral Flexibility 142

Introgressive Hybridization 145

Hybridization and Animal Breeding 146

Environmental Conditions Conducive to Introgression 146

Finches versus Mockingbirds 148

Summary 150

CHAPTER TWELVE: The Life History of Adaptive Radiations 152

Introduction 152

The First Stage of Adaptive Radiation 153

The Second Stage of Adaptive Radiation 154

Haldane's Rule 157

The Third Stage of Adaptive Radiation 158

Synthesis 160

Summary 162

CHAPTER THIRTEEN: Summary of the Darwin's Finch Radiation 163

What Happened and Why 163

What Is Missing? 165

Epilogue 166

Glossary 168

References 175

Author Index 201

Subject Index 210

What People are Saying About This

Endler

I really enjoyed this book. It is a splendid introduction both to the finches and to radiation on islands. The authors' statement that 'Speciation is a process and not an event' should become one of the most famous quotes in evolutionary biology.
— John A. Endler, University of California, Santa Barbara

From the Publisher

"I really enjoyed this book. It is a splendid introduction both to the finches and to radiation on islands. The authors' statement that 'Speciation is a process and not an event' should become one of the most famous quotes in evolutionary biology."—John A. Endler, University of California, Santa Barbara

"A brilliant synthesis. The authors have written a concise summary of current understanding of one of the classic case studies of evolutionary diversification, Darwin's finches of the Galápagos. I can think of no parallel to this work. This book will be an inspiration to students. The Grants' love of the subject and the research comes through clearly."—Jonathan B. Losos, Harvard University

"This is a book that summarizes decades of research on Darwin's finches and integrates it into a very accessible synthesis. What really distinguishes the book, of course, is the authority of the authors, who have lived with these birds for many years and have unparalleled familiarity with them. Readers will benefit enormously from the scholarship in this book."—David B. Wake, University of California, Berkeley

Losos

A brilliant synthesis. The authors have written a concise summary of current understanding of one of the classic case studies of evolutionary diversification, Darwin's finches of the Galápagos. I can think of no parallel to this work. This book will be an inspiration to students. The Grants' love of the subject and the research comes through clearly.
— Jonathan B. Losos, Harvard University

Wake

This is a book that summarizes decades of research on Darwin's finches and integrates it into a very accessible synthesis. What really distinguishes the book, of course, is the authority of the authors, who have lived with these birds for many years and have unparalleled familiarity with them. Readers will benefit enormously from the scholarship in this book.
— David B. Wake, University of California, Berkeley

Editorial Reviews

"The authors' assertion that 'speciation is a process and not an event,' comes across clearly in this concise and accessible tale of 3 million years of finch evolution."

Science News

The book is valuable as a condensed version of the huge amount of fine work the authors have done on the finches. It should be accessible to scientists and informed lay audiences alike. The theory and ecological aspects are very compelling.

Bioscience - Robert M. Zink

How and Why Species Multiply is so impressive and such a stimulating read for two primary reasons, the first being the data presented throughout the work. Rarely do we have such detailed data on any natural system and the book draws great strength from this. The second reason is the commanding role given to ecological interactions in explaining the evolutionary dynamics of Darwin's finches.

Ibis - Utku Perktas

[T]he book is authoritative, well prepared and edited . . . and attractive. The Grants have provide and excellent third part for the Darwin's finch trilogy, and this volume should serve admirably as a summary of the knowledge that they have accumulated.

Quarterly Review of Biology - A. Townsend Peterson

This book presents a succinct and most readable summary of one of the most important contemporary field experiments in evolution and adaptive radiation. It should be basic reading for any biologist.

Biologist - Ghillean Prance

The book illustrates how laboratory work, particularly in developmental biology and molecular genetics, can be combined effectively with observations and experimental work in the field.

Choice

Distilled into 200 pages, this is the life's work of two of evolutionary biology's greatest advocates, Peter and Rosemary Grant. In this book they meld insights from geography, behaviour, ecology and genetics to paint a complex but compelling picture of the evolutionary process. [A] must-have primer for any biology student.

New Scientist - Henry Nicholls

This Princeton-based couple presents their own accessible summary of their life's research in How and Why Species Multiply. The authors explain the scientific hypotheses involved...with admirable clarity...yet the book's real strength is not theory but data. The Grants' account makes exciting and lucid reading. Among those who should take note are doubters of 'old-fashioned' research methods who marvel at the prospects of genomics in the lab and wonder what use bird bands have in modern science.

Science - Hanna Kokko

One of the most compelling documentations of the operation of natural selection. In this book, the Grants aim to capture the key insights provided by Darwin's finches into mechanisms of adaptation and speciation generally. They succeed in making a complex topic accessible without losing the excitement inherent in tackling a difficult problem. There is enough depth to stimulate serious students of evolutionary biology, enough explanation for general readers and an approachable style that will please both.

Times Higher Education - Roger Butlin

The book illustrates how laboratory work, particularly in developmental biology and molecular genetics, can be combined effectively with observations and experimental work in the field.

S. Schwartz

The book is valuable as a condensed version of the huge amount of fine work the authors have done on the finches. It should be accessible to scientists and informed lay audiences alike. The theory and ecological aspects are very compelling.
— Robert M. Zink

Bioscience

How and Why Species Multiply is so impressive and such a stimulating read for two primary reasons, the first being the data presented throughout the work. Rarely do we have such detailed data on any natural system and the book draws great strength from this. The second reason is the commanding role given to ecological interactions in explaining the evolutionary dynamics of Darwin's finches.
— Utku Perktas

Ibis

[T]he book is authoritative, well prepared and edited . . . and attractive. The Grants have provide and excellent third part for the Darwin's finch trilogy, and this volume should serve admirably as a summary of the knowledge that they have accumulated.
— A. Townsend Peterson

Quarterly Review of Biology

This book presents a succinct and most readable summary of one of the most important contemporary field experiments in evolution and adaptive radiation. It should be basic reading for any biologist.
— Ghillean Prance

Biologist

Distilled into 200 pages, this is the life's work of two of evolutionary biology's greatest advocates, Peter and Rosemary Grant. In this book they meld insights from geography, behaviour, ecology and genetics to paint a complex but compelling picture of the evolutionary process. [A] must-have primer for any biology student.
— Henry Nicholls

New Scientist

This Princeton-based couple presents their own accessible summary of their life's research in How and Why Species Multiply. The authors explain the scientific hypotheses involved...with admirable clarity...yet the book's real strength is not theory but data. The Grants' account makes exciting and lucid reading. Among those who should take note are doubters of 'old-fashioned' research methods who marvel at the prospects of genomics in the lab and wonder what use bird bands have in modern science.
— Hanna Kokko

Science

One of the most compelling documentations of the operation of natural selection. In this book, the Grants aim to capture the key insights provided by Darwin's finches into mechanisms of adaptation and speciation generally. They succeed in making a complex topic accessible without losing the excitement inherent in tackling a difficult problem. There is enough depth to stimulate serious students of evolutionary biology, enough explanation for general readers and an approachable style that will please both.
— Roger Butlin

Times Higher Education

Peter and Rosemary Grant – Winners of the 2017 Royal Medal in Biology, The Royal Society

"One of the most compelling documentations of the operation of natural selection. In this book, the Grants aim to capture the key insights provided by Darwin's finches into mechanisms of adaptation and speciation generally. They succeed in making a complex topic accessible without losing the excitement inherent in tackling a difficult problem. There is enough depth to stimulate serious students of evolutionary biology, enough explanation for general readers and an approachable style that will please both."—-Roger Butlin, Times Higher Education

"This Princeton-based couple presents their own accessible summary of their life's research in How and Why Species Multiply. The authors explain the scientific hypotheses involved...with admirable clarity...yet the book's real strength is not theory but data. The Grants' account makes exciting and lucid reading. Among those who should take note are doubters of 'old-fashioned' research methods who marvel at the prospects of genomics in the lab and wonder what use bird bands have in modern science."—-Hanna Kokko, Science

"Distilled into 200 pages, this is the life's work of two of evolutionary biology's greatest advocates, Peter and Rosemary Grant. In this book they meld insights from geography, behaviour, ecology and genetics to paint a complex but compelling picture of the evolutionary process. [A] must-have primer for any biology student."—-Henry Nicholls, New Scientist

From the Publisher