Final Report Summary - SEXUAL CONFLICT (Genetic architecture of intralocus sexual conflict in a wild bird population)
Sex-specific quantitative genetic parameters (additive genetic (co)variances) and selection coefficients were estimated for a set of sexually dimorphic morphological traits (bill width, bill length, wing length, tarsus length) using pedigree and lifetime reproductive success (LRS) data collected over multiple decades. A multivariate statistical framework was then used to predict micro-evolutionary responses and estimate the fitness consequences of sex-specific effects. Results indicated that studied morphological traits were highly heritable and generally influenced by the same genes in both sexes. Selection analyses indicated the presence of significant multivariate selection, without any evidence for a sex by selection interaction. Together, sex-specific additive genetic effects and multivariate selection generated predicted genetic variance in relative fitness explaining less than 1% of the phenotypic variation in relative fitness. Cross-sex genetic covariances were found to (non-significantly) increase the predicted rate of adaptation relative to a situation where traits were not genetically correlated between the sexes. Finally, the presence of separate genders, relative to a situation where there would be no sex-specific selection and genetic variance, was found to result in a decrease in the predicted rate of adaptation.
Overall, this research project made significant contributions to our understanding of the evolutionary dynamic of sexual dimorphism in an important ecological model organism. It also contributed to the development of a multivariate framework to quantify the fitness consequences of sex-specific selection in wild populations. Increased knowledge about the genetic basis of sex-specific fitness will allow for a better understanding of the role of sexually antagonistic selection in maintaining genetic variation, developing more realistic sexual selection models, better understanding population dynamics and assessing the importance of sexual dimorphism in the speciation process. General knowledge about the genetic basis and evolutionary dynamic of sexual dimorphism is also highly pertinent to plant and animal breeding as well as human medical genetics.