All biology only makes sense when seen in the light of evolution, and this is especially true for the nervous system. All animals have nervous systems that mediate their behaviors, many of them species specific. Yet, these nervous systems all evolved from the simple nervous system of a common ancestor. To understand these nervous systems, we need to know how they vary and how this variation emerged in evolution. Over 100 distinguished neuroscientists have assembled, for the first time, the current state-of-the-art knowledge on how nervous systems evolved throughout the animal kingdom. This four-volume overview is rich in detail and broad in scope, and outlines the changes in brain and nervous system organization that occurred from the first vertebrates to present day fishes, reptiles, birds, mammals, and especially primates, including humans. The basic principles of brain evolution are discussed, as well as mechanisms of change, which involved gene expression and altered the courses of embryonic development. The reader can select from chapters on highly specific topics as well as those providing an overview of current thinking and approaches. This unique major reference promises to become the gold standard for those interested in evolution and in nervous systems. It is also available online via ScienceDirect (2006) featuring extensive browsing, searching, and internal cross-referencing between articles in the work, plus dynamic linking to journal articles and abstract databases, making navigation flexible and easy. It broadly covers topics ranging from genetic control of development in invertebrates to human cognition. It incorporates the expertise of over 100 outstanding investigators who provide their conclusions in the context of the latest experimental results. It presents areas of disagreement as well as consensus views.