Cichlids are an example of what Mary Jane West-Eberhard calls a “multidirectional radiation” – that is an adaptive radiation that produces a large amount of diversity and specialization of related forms. There are at least 1,500 species of haplochromine cichlids. Within Lake Victoria there are at least 120 species that display a wide variety of behavioral and morphological specializations.
Over at UD Pav has totally misunderstood a paper by the Grants on the Evolution of Character Displacement in Darwin’s Finches. Having just reviewed a book by the Grants I was looking forward to ripping into some creationist mumbo jumbo. Alas, it is not to be.
I am almost finished reading Peter Grant’s “Ecology and Evolution of Darwin’s Finches”. As is well known, the finches on the Galapagos Islands provided Darwin with one of the final pieces in the puzzle of the origin of species and are considered a model demonstration of the effects of natural selection. Grant’s book provides a concrete illustration of the correct way to apply evolutionary theory to solve ecological problems. Starting with an overview of the various genre and species on the Galapagos Islands the book moves through environment conditions and feeding behavior, demonstrating how each has an impact on species distribution. Along the way, Grant reviews previous studies of Darwin’s finches and provides exhaustive references for anyone who wants to explore the question in more detail. Finally, Grant discusses species distribution in terms of adaptive radiation and considers various scenarios whereby the islands were populated. Although one should have some familiarity with ecology and biology, the book can be read by anyone. I highly recommend the book!