Eastern Red-Backed Salamanders: A Comprehensive Review of an Undervalued Model in Evolution, Ecology, and Behavior

What makes a model organism? Identifying the qualities of a model organism has been given a great deal of attention in the biomolecular sciences, but less so in the fields of evolution, ecology, and behavior (EEB). In contrast to the biomolecular sciences, within EEB, biotic and abiotic variation are features to understand, not bugs to get rid of, and EEB scientists often select organisms to study which best suit the scientific question at hand. Successful EEB model organisms can be studied at multiple biological scales and often have a wealth of accumulated knowledge on which current research programs build. A recent call within EEB communities to invest in the development of diverse model systems led us to evaluate the standing of a widespread, abundant, terrestrial salamander in this review: the Eastern Red-backed Salamander (Plethodon cinereus). We first look at salamanders as EEB models more generally and determine where P. cinereus fits in this broader context. The core of our monograph reviews over 400 recent studies on P. cinereus and highlights inconsistencies, gaps in our knowledge, and future directions in the context of our findings and those of three prior comprehensive reviews: two comprehensive reviews published in 1998 and 2013, and a book published in 2016 focused on the behavioral ecology of P. cinereus. After completing our review, we conclude by evaluating the current status of P. cinereus as a model organism in EEB and describe how a collaborative research network, SPARCnet, can serve as a starting point for improving the range-wide understanding of P. cinereus ecology, evolution, and behavior. More generally, we argue that collaborative research networks can and should be applied to other EEB model systems, so that future EEB research may benefit from model systems that accurately represent, in Darwin's words, “endless forms most beautiful and most wonderful.”