Symposium: The Evolution of Thermal Reaction Norms for Growth Rate and Body Size in Ectotherms

Society For Integrative And Comparative Biology, Herndon VA

Investigators

Abstract

Symposium: The Evolution of Thermal Reaction Norms for Growth Rate and Body Size in Ectotherms Michael J. Angilletta Jr. and Michael W. Sears Indiana State University In recent years, a major goal of evolutionary biologists has been to understand how spatial and temporal variation in the environment impacts the evolution of traits. In particular, a resurgence of interest in the relationship between environmental temperature and organismal body size has occurred. Biologists have documented a pervasive trend within ectotherms: in general, individuals in colder environments attain larger body sizes at adulthood than individuals in warmer environments. Underlying this widespread relationship between temperature and body size are behavioral and physiological mechanisms that govern the rates of growth and maturation. Recent studies have revealed that these mechanisms can evolve rapidly in response to variation in the thermal environment. These empirical findings have triggered a burst of activity by theorists who are trying to explain the evolution of temperature-size relationships. Yet, in spite of the renewed interest in this area of research, empirical and theoretical efforts are still largely unsynchronized. Consequently, evolutionary explanations remain elusive. This grant will fund a symposium that unites researchers investigating the causes of relationships among temperature, growth rate, and body size. The goals of the symposium are threefold: 1) to identify the tradeoffs and constraints that influence the evolution of growth rate and body size in different thermal environments, 2) to determine if the factors that influence temperature-size relationships in well-studied species can be generalized to other species, and 3) to discuss how these factors can be incorporated into existing theories. Through this symposium, a new paradigm for understanding the evolution of traits in variable environments will be developed, and links between researchers from different disciplines that are necessary to advance this paradigm will be established. The participants include theorists and empiricists who are taking different approaches to the study of evolution in diverse organisms. Moreover, these participants range from some of the most promising postdoctoral fellows to well-established leaders in the field of evolutionary biology. Given the sharp focus of the symposium and the diversity of participants, the symposium should spark a synthesis of ideas about the evolution of reactions norms that can diffuse rapidly throughout the relevant branches of the scientific community.