What Salamanders Have Taught Us About Evolution

Taxon-based research in evolution permits the development of a multidimensional approach, illustrated here with lessons learned from research on salamanders. The clade is widespread and diverse, yet sufficiently small that one can keep all of the species in mind. This facilitates research from diverse perspectives: systematics and phylogenetics, morphology, development, ecology, neurobiology, behavior, and physiology. Different avenues of research offer unique perspectives on how a relatively old vertebrate clade has diversified. An integrated, hierarchically organized, multi dimensional program of research on a taxon illuminates many general principles and processes. Among these are the nature of species and homology, adaptation and adaptive radiations, size and shape in relation to issues in organismal integration, ontogeny and development in relation to phylogeny, the ubiquity of homoplasy, ecological niche conservation, species formation, biodiversity, and conservation. Opportunities for future research and threats to the continued existence of salamanders are briefly outlined.