Meeting Abstract

40.2  Wednesday, Jan. 5  The evolution of acclimation of thermal performance CONDON, CH*; CHENOWETH, SF; WILSON, RS; The University of Queensland, Australia c.condon@uq.edu.au

Many ectotherms have the capacity to alter the thermal dependence of a trait after a short period of acclimation to a new environment. Seasonal acclimation of performance traits in vertebrate ectotherms is often thought to be adaptive, yet most studies fall short of demonstrating the link between acclimation and fitness. While direct tests of evolutionary hypotheses of the benefit (or otherwise) of acclimation are much more frequent than in previous years, very little is known about the genetic architecture of thermal performance functions and acclimation. Only a handful of studies have examined the genetic (co)variance in thermal performance curves or the genetic basis of thermal acclimation. Here, we have used a multivariate genetic analysis to test hypotheses of the evolution of thermal acclimation. We tested the thermal dependence of a locomotor performance and a behavioural trait within and among families of the zebrafish (Danio rerio) that were acclimated to two different thermal environments. In addition, we also examined the genetic variance in the acclimation of biochemical traits that underlie locomotor performance. We used a classical quantitative genetic analysis to test for genetic (co)variance in performance at 8 temperatures and between the two acclimation environments. In addition, we utilised a function-valued analysis to examine the genetic variation in performance curve shape. We will discuss the genetic correlations between curve components and the genetic variances and covariances of each trait that influence the evolution of acclimation.