The structure of the ribosome will be investigated as a source of information for reconstructing the evolutionary history of vertebrates, especially salamanders. The evolutionary relationships inferred from these data will permit evaluation of the mechanisms of molecular evolution, organismal evolution and speciation that have been utilized during vertebrate evolution. This information will be particularly useful for investigating the developmental mechanisms by which novel, adaptive features are produced by the evolutionary process. Resolution of evolutionary relationships will permit the construction of a more stable and useful taxonomic classification for the species studied. This study will identify which parts of the ribosome are likely to be most informative for evaluating evolutionary relationships across a broad spectrum of evolutionary time, thereby facilitating evolutionary studies of additional taxa.