During his voyage, Charles Darwin famously failed to realize the significance of the different beaks of the various Galápagos finches. He visited the archipelago for five weeks in 1835, but it was not until he got back to London that it occurred to him that the finches might originally have been the same species, and that their beaks had evolved in response to the different foods available on the widely separated islands. Darwin’s account of his time in the Galápagos Islands in "The Voyage of the Beagle" is consequently rather matter-of-fact. He certainly had no idea that the small, drab birds he was collecting were going to revolutionize the science of biology.
Jonathan Weiner, on the other hand, enjoyed the benefit of hindsight when he came to write "The Beak of the Finch," for which he won a Pulitzer Prize in 1995. His book describes the research of two Princeton scientists, Peter and Rosemary Grant, who for two decades spent a portion of each year studying the finches on a precipitous rock called Daphne Major. Weiner’s story is a thrilling piece of science writing. The Grants observed that the harsh conditions in the Galápagos resulted in frequent catastrophic collapses in the finch populations, which would then be rapidly rebuilt by the few remaining individuals.
As a result, evolutionary changes made possible by inherited characteristics were dramatically accelerated and could be observed in a matter of months or years, rather than over millennia. In 2014, the Grants published their own account of their research in "40 Years of Evolution: Darwin’s Finches on Daphne Major Island."