The Ecology of Adaptive Radiation

Abstract Adaptive radiation is a spectacular feature of evolution. It is also widespread, more so than the list of familiar cases, including the Galapagos finches, the cichlid fishes of East African lakes, and the Hawaiian silversword alliance, alone would suggest. Much of life’s diversity, perhaps even most of it, has arisen during similar episodes of speciation and phenotypic and ecological divergence. My main goal in this book is to assess how far we have come in understanding the causes of this remarkable process. Before I began the book I held the naive notion that my years of study on the Galapagos finches, where my fascination with adaptive radiation began, on African and American finches, and more recently on fishes of postglacial lakes, had taught me enough about adaptive radiation that my task would involve little more than writing down all I knew before I forgot it. As the book got underway the limits of my knowledge became distressingly apparent, and I now feel I learned most of its contents along the way. Here I aim to put the results of many studies together to ask whether they conform or contra st with the dominant ‘ecological’ theory of adaptive radiation that was formulated in the first half of the last century.