EVIDENCE OF GENETIC ISOLATION BETWEEN SEXUALLY MONOMORPHIC AND SEXUALLY DIMORPHIC TRAITS IN THE WATER STRIDER AQUARIUS-REMIGIS

Estimates of multivariate selection are becoming increasingly common i n the literature. Although it is clearly recognized that genetic infor mation is essential to understanding natural selection, few studies in clude estimates of genetic parameters. Previous studies of the water s trider Aquarius remigis have demonstrated selection on body size and c omponents of body size that may favour the evolution and maintenance o f sexual size dimorphism. In this paper we present quantitative geneti c estimates of heritabilities and genetic correlations for male and fe male A. remigis. Overall body size (total length) and the majority of components of body size were significantly heritable for both sexes an d the shape of the genetic correlation matrix was similar between the sexes. However, patterns of genetic correlations between the sexes and analysis of genetic integration suggest that some traits may be genet ically isolated.