NCSE is pleased to offer a free preview (PDF) of Peter R. Grant and B. Rosemary Grant's How and Why Species Multiply (Princeton University Press, 2007, reissued in paperback in 2011). The preview consists of chapter 10 — "Reconstructing the Radiation of Darwin's Finches" — in which Grant and Grant "attempt to interpret the radiation of Darwin's finches by paying attention to the ecological circumstances in which different speciation cycles took place." They summarize, "The radiation unfolded with an increase in number and diversity of species in a changing environment, and it was molded by natural selection, introgressive hybridization, and extinction. An increase in number of islands increased the opportunities for speciation and thereby the number of species. A change in climate and altered vegetation increased the opportunities for new types of species to evolve."
Famous for their sustained work on Darwin's finches (as recounted for a popular audience in Jonathan Weiner's Pulitzer-prize-winning The Beak of the Finch), Peter R. Grant and B. Rosemary Grant are professors emeriti at Princeton University; among their honors are the 2005 Balzan Prize, the Darwin-Wallace Medal of the Linnean Society in 2008, and the 2009 Kyoto Prize. The reviewer for New Scientist described their book as "a must-have primer for any biology student," and David B. Wake praised How and Why Species Multiply as "a book that summarizes decades of research on Darwin's finches and integrates it into a very accessible synthesis. What really distinguishes the book, of course, is the authority of the authors, who have lived with these birds for many years and have unparalleled familiarity with them. Readers will benefit enormously from the scholarship in this book."