Evolution in Action: Darwin's Finches of the Galápagos Islands

Peter R. Grant & Rosemary Grant

Subjects of the Pulitzer Prize-winning book, The Beak of the Finch, Peter and Rosemary Grant discuss their 20 years of fascinating research into evolution, ecology and behavior among Darwin's Finches of the Galápagos Islands. Distinguished Visting Fellows in the College of Creative Studies, the Grants are professors at Princeton University.

In his profound and elegantly written book, Weiner follows the progress of the Grants during their decades-long study on Daphne Major, an island in the Galápagos archipelago, where Darwin conceived of his theory of evolution. Their observations of Darwin's Finches ultimately lead them to a new understanding of life itself.

On an island characterized by sheer cliffs and no fresh water, and devoid of human interference into natural selection, the Grants documented some 13 species of "Darwin's Finches," including one that is flightless; one that cohabits with marine iguanas; one (the vampire finch) that lives on blood; one that is entirely vegetarian; and one (the cactus finch) that makes tools with its beak.

The Grants caught and banded thousands of finches and traced their elaborate lineage, enabling them to document the changes that individual species make, primarily to their beaks, in reaction to the environment. During prolonged drought, for instance, beaks may become longer and sharper, to reach the tiniest of seeds.

Peter and Rosemary Grant began their investigation of evolutionary change among Darwin's Finches in 1973. They have studied more than 25 generations of finches—more than 19,000 individual birds. The Galápagos finches have been perfect objects of study because of their tameness and the simplicity of their undisturbed habitats.

Peter Grant writes, "I seek an understanding of the origin of new species, their ecological interactions, their persistence in different communities and their ultimate extinction." He is currently investigating the causes, frequency and consequences of hybridization and inbreeding. In addition, he is trying to make sense of patterns of Darwin's Finch diversification. He says of himself, his partner/wife and their students, "Our current work is aimed at illuminating the details and causes of early branching in the tree of Darwin's Finches.".

Program recording date and length: 5-21-01 ~ 1 Hour 26 Minutes

Order Catalog No.: 3400-C