This book succinctly reviews phylogenetic debates for fishes by considering the historical background, summarizing the controversies, sorting through and evaluating competing modern phylogenetic proposals, and synthesizing the results for each major fish group. It evaluates the leading hypotheses in terms of their significance and their implications for the comparative biology of fishes. It asks whether phylogeny makes sense and examines its ability to explain the known facts about a group of fishes. Key selling features: Organizes a complex subject and presents it in a simple way Focuses on the latest research and the most current ideas Contains illustrations of evolutionary relationships in the form of simplified trees Illustrates important morphological innovations that characterize particular fish groups Highlights well-known species that people can relate to placing them in their evolutionary context (e.g., white shark, rainbow trout, seahorse, Atlantic cod) species that people can relate to placing them in their evolutionary context (e.g., white shark, rainbow trout, seahorse, Atlantic cod).