Evolutionary novelties: How fish have built a heater out of muscle

Abstract

The evolution of any complex morphology or physiological adaptation involves the historical transformation of numerous interacting components from an ancestral to a derived state. How such transformations occur are central to our understanding of how novel morphologies arise. The rapid explosion of technology in the field of molecular biology provides new tools that can be incorporated into studies examining the origin of novel phenotypes. Molecular biological techniques can now be used to probe how changes in gene expression result in pathways leading to novel or altered morphologies. The integration of molecular approaches into problems in organismal biology provides a promising new direction for the analysis of form and function. Interdisciplinary studies, combining the resolving power of molecular biologywith the complex problems of organismal biology, will shed new light on whole animal function and evolution. © 1991 by the American Society of Zoologists.