Speciation is the process by which co-existing daughter species evolve from one ancestral species - e.g., humans, chimpanzees, and gorillas arising from a common ancestor around 5,000,000 years ago. However, many questions about speciation remain controversial. The Birds of Northern Melanesia provides by far the most comprehensive study yet available of a rich fauna, composed of the 195 breeding land and fresh-water bird species of the Bismarck and Solomon Archipelagoes east of New Guinea. This avifauna offers decisive advantages for understanding speciation, and includes famous examples of geographic variation discussed in textbooks of evolutionary biology. The book results from 30 years of collaboration between the evolutionary biologist Ernst Mayr and the ecologist Jared Diamond. It shows how Northern Melanesian bird distributions provide snapshots of all stages in speciation, from the earliest (widely distributed species without geographic variation) to the last (closelyrelated, reproductively isolated species occurring sympatrically and segregating ecologically). The presentation emphasizes the wide diversity of speciation outcomes, steering a middle course between one-model-fits-all simplification and ungeneralizable species accounts. Questions illuminated includ