Recent studies have discovered considerable genetic and morphological variation between and within populations of the same species. Yet the relation between this intraspecific variation and the processes of speciation remains poorly understood. When, how, and why do new species arrive?Evolution of Biological Diversity, with a prominent assortment of contributors, is an extensive review of the most recent research into this and other questions of biological diversity and the processes of speciation. Major chapters explore how variation occurs within species by emphasizing the ecological and...