Wednesday, March 26, 2008

Right before our eyes

Some of us will remember the terrific 1994 book by Jonathan Weiner, The Beak of the Finch, about the 14 or so species of finches that inhabit the Galapagos Islands off the coast of Ecuador. They are known as "Darwin's finches" because of the role they might have played in suggesting to the great biologist certain key ideas of evolution by natural selection. The beaks of the finches are marvelously adapted to their food sources -- large beaks crunch big seeds more effectively, but large-beaked birds are at a disadvantage when seeds are small, and so on. The finches presumably derived from an initial population that arrived at the Galapagos from the mainland, then diversified and speciated on the various islands. Weiner's book was based largely on the work of Peter and Rosemary Grant, who at that time had been studying the finches for more than 16 years -- banding birds, measuring beaks and body parts, locating nests, recording songs, keeping track of climate, food sources, competition, mate choice, and so on.

Now the Grant's have published their own account of more than 30 years of research, How and Why Species Multiply: The Radiation of Darwin's Finches, and I can't wait to get my hands on a copy. From Weiner's account of their work, we can expect a stunning compilation of data painstaking gathered over three decades, as climate and vegetation changed in response to swings in El Nino, all of which (according to reviews) is consistent with the basic insights of an insatiably curious young man who visited the islands 173 years ago. The armchair anti-evolutionists who want to deprive our public school children exposure to one of the great insights of human genius might profitably read the Grants' book to see how real science is done.