Peter R. Grant and B. Rosemary Grant

40 years of evolution : Darwin's finches on Daphne Major island

Princeton university press

Princeton (NJ), 2014

bibliothèque insulaire

îles désertes
bestiaire insulaire
parutions 2014
40 years of evolution : Darwin's finches on Daphne Major island / Peter R. Grant and B. Rosemary Grant. - Princeton (NJ) : Princeton university press, 2014. - XXXII-400 p. : ill., maps ; 25 cm.
ISBN 978-0-691-16046-7
Au centre de l'archipel des Galápagos, à quelques kilomètres au nord de l'île de Santa Cruz, Daphne Major est le sommet émergé d'un ancien volcan. L'îlot mesure moins d'un kilomètre dans sa longueur et culmine à 120 mètres au-dessus du niveau de la mer ; il n'a jamais été habité, et n'héberge que de rares espèces animales et végétales, au nombre desquelles quelques dizaines de couples de ces pinsons (Geospiza fortis, G. fuliginosa, G. magnirostris, G. scandens), dont, au XIXe siècle, Darwin a relevé la présence dans l'archipel : ceux qui l'ont conduit à élaborer sa théorie de l'évolution.

Un couple de chercheurs américains a consacré 40 ans à l'observation de ces modestes oiseaux, accumulant une somme considérable de données précieuses qui prolongent, précisent et font vivre l'intuition de leur grand prédécesseur. Si l'ouvrage est prioritairement destiné aux spécialistes, chacun peut y trouver matière à enrichir sa connaissance et sa réflexion : au cœur du Pacifique, les pinsons sont les acteurs d'une histoire de portée universelle, qui reste ouverte : Darwin finches have much more to teach us (p. 318).
PUBLISHER'S DESCRIPTION : 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.

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.
CONTENTS Darwin's finches on the Galápagos islands are a model system for the study of speciation and adaptive radiation, that is, the rapid evolution of morphologically and ecologically diverse species from an ancestor. Core ingredients of a theory to explain how and why the radiation occurred are natural selection, allopatric divergence, reproductive isolation, and interspecific competition. Our task is to determine how these ingredients occur, and how they are connected. In this book we describe what we learned about evolution by studying four species of ground finches on the single island of Daphne Major over a period of 40 years.

Chapter One, p. 16

Early problems, early solutions

1— Speciation, adaptative radiation, and evolution
2— Daphne finches : a question of size
3— Heritable variation
4— Natural selection and evolution
5— Breeding ecology and fitness

Developing a long-term perspective

6— A potential competitor arrives on Daphne
7— Competition and character displacement
8— Hybridization
9— Variation and introgression

Hybridization and speciation

10— Long-term trends in hybridization
11— Long-term trends in natural selection
12— Speciation
13— Speciation by introgressive hybridization


14— The future of finches on Daphne
15— Themes and issues
16— Generalization
17— Epilogue

Abbreviations, Glossary, References, Subject index
  • Charles Darwin, « On the origin of species by means of natural selection, or The preservation of favoured races in the struggle for life », London : John Murray, 1859
  • Charles Darwin, « Journal de bord [Diary] du voyage du Beagle (1831-1836) », Paris : Honoré Champion (Classiques : essais), 2012
  • Charles Darwin, « L'archipel des Galápagos » Ch. XVII du Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world (2nd ed., 1845), trad. par Michel Imbert, in Herman Melville, Les îles enchantées, Marseille : Le Mot et le reste, 2015
  • Peter R. Grant, « Ecology and evolution of Darwin's finches », Princeton (NJ) : Princeton university press, 1986, 1999
  • Peter R. Grant and B. Rosemary Grant, « Evolutionary dynamics of a natural population : the large cactus finch of the Galápagos », Chicago : University of Chicago press, 1989
  • Peter R. Grant and B. Rosemary Grant, « How and why species multiply : the radiation of Darwin's finches », Princeton (NJ) : Princeton university press, 2008
  • Jonathan Weiner, « The beak of the finch : a story of evolution in our time », New York : Knopf, 1994
d'autres regards sur les îles Galápagos

mise-à-jour : 2 juin 2016

Daphne Major, with Daphne Minor (Chica) in the background (p. XXVIII)