I am interested in applying genomic techniques to solve classic and applied questions in evolutionary genetics. My current focus at CIGENE is on the impact of aquaculture escapees on wild populations. As part of this work we are investigating the genomics of ecologically relevant variation in wild salmon populations.
We recently discovered two loci that influence age at maturity, a major fitness related trait, in wild Atlantic salmon. One of these is a major effect locus that is the focus of sexual conflict and represents the first known example of sex-dependent dominance, a potentially key genetic mechanism for maintaining sexually antagonistic variation in the absent of differentiated sex chromosomes. This work has highlighted the importance of sexual conflict for the maintenance of fitness variation in salmon, but there is much left to understand, for instance, how sexual conflict and spatially varying selection with gene flow interact and how the sex-dependent dominance pattern is controlled. We hope that through an improved understanding of these processes we will be able to achieved a better understanding of the vulnerability of natural salmon populations to introgression from aquaculture escapees and other potential threats and how vulnerability varies among populations.
My previous work has focused on contemporary and rapid evolutionary change, especially in the presence of gene flow. I have worked on contemporary life history adaptation of European grayling to a novel thermal regime and the establishment of barriers to gene flow through isolation by distance and time following colonisation of a new lake system. I investigated the population genetic structure of the guppy, Poecilia reticulata, in upland rivers, which typically have unidirectional gene flow with inbreeding in the head waters. We used this structure to analyse the impact of genetic drift on the maintenance of immunogenetic fitness variation by negative frequency dependent balancing selection. My PhD tested the assumptions of models of sympartric speciation by sexual selection using a sympatic cichlid species pair from the explosive radiation of Lake Malawi.