We are now in the Fourth Edition of Herpetology, and advances in the field have been remarkable. The global interest in herpetology has increased dramatically, with new professional societies emerging in nearly every country and literally thousands of bright, enthusiastic herpetologists entering the field. Perusal of nearly every scientific jour-nal reveals author lines with new names, many of which will make significant contributions to the field throughout their entire careers. Technological and analytical advances in phylogenetics have not only resulted in new phylogenetic hypotheses for clades of amphibians and reptiles, but have resulted in reinterpretations of ecological and behavioral phenomena. Most striking is the impact of phylogenetics on historical biogeography and related fields. Not only can we trace the history of clades on a global level, we can also add a time component to the divergence histories of clades based on evolutionary rates of genes. These independently derived divergence histories can then be used to integrate the evolution of clades with the geological history of the planet.