Meeting Abstract

P2.64  Jan. 5  Genic capture, environmental variation and good genes in gray tree frogs WELCH, A.M.**; SMITH, M.J.; GERHARDT, H.C.; College of Charleston, SC; Arthur Rylah Institute, Victoria, AUS; Univ. of Missouri, Columbia welcha@cofc.edu

Several hypotheses have been proposed to explain the maintenance of genetic variation in sexually-selected traits. The genic-capture model predicts that condition-dependent traits can �capture� genetic variation in condition, which is assumed to be a composite of many traits and, hence, to encapsulate genetic variation from many loci. Genetic variation in sexually-selected traits could also be maintained by genotype-by-environment (GxE) interactions, especially in heterogeneous or fluctuating environments. These two processes may act synergistically. Specifically, condition�given its composite nature�reflects the contributions of many genes, and these genes may have different effects in different environments. Together, these models predict abundant genetic variation in condition, genetic covariance between condition and sexually-selected traits, and GxE interactions that affect condition and, consequently, sexually-selected traits. We are testing these predictions in gray tree frogs by rearing, in two developmental environments, the offspring of males that vary in call duration, a sexually-selected trait. We are comparing body sizes of offspring from these sires to estimate genetic variation in offspring condition and to determine whether this among-genotype variation is consistent across environments. We are also testing the degree to which genetic variation in condition is associated with variation in sire call duration and whether this association varies across environments. Our goal is to assess the relative effects of genotype, environment and GxE interaction on offspring condition, in order to evaluate the potential roles of environmental variation and condition dependence in the evolutionary dynamics of a sexually-selected trait.