Abstract of the Commemorative lecture
In Charles Darwin's Footsteps
Charles Darwin visited the Galápagos archipelago for five weeks in 1835. His observations on animals, plants and volcanoes contributed to the development of his revolutionary ideas about evolution by natural selection. Finches, now known as Darwin's finches, were an important element in his thinking. We have been visiting Galápagos every year for the last 37 years in order to understand in detail how the ancestral species of finch, arriving in the archipelago two to three million years ago, gave rise to the 13 species of Darwin's finches living there today.
Each of us grew up in England and experienced nature in the countryside. We received our undergraduate training in Britain, then migrated to the University of British Columbia where we met. Many years later, after we had married, obtained a job at McGill University in Canada, and started a family, we launched a program of field research on the Galápagos islands. Our previous training had been different: Peter had specialized in ecology and Rosemary had specialized in genetics. These separate fields of expertise enabled our joint research to be more than the sum of the parts. The interaction between our different ways of thinking about problems gave us greater insights than either of us would have reached alone by staying within our own respective fields.
The research was initially designed to address three questions. First, how do new species form? Second, has competition between species been important in their evolution? Third, why do some populations vary much more than others in characteristics such as beak or body size? To answer them we combined a study of different finch communities on several islands in the archipelago with a study in great detail on the islands of Genovesa for 11 years and Daphne Major for 37 years: patterns in space combined with processes in time. Our most important finding has been that evolution by natural selection can be observed, measured and interpreted, and it occurs repeatedly when the environment changes. Darwin would have been surprised, since he believed that evolution occurred too slowly for anyone to see, but would have been delighted.
