Project title and description
,,The genomic basis of adaptive differentiation between closely related morphs of Arctic charr”.
To what extent do loci with moderate to large effects on phenotype contribute to adaptive differentiation between ecotypes of Arctic charr specialising on foraging for different prey types in different environments within Thingvallavatn? Are loci related to adaptive differentiation fixed, or do they cause variation both between and within morphs? Are there evidence of positive selection in the genome? Do genomic regions with signatures of selection also associate with phenotype? These and related questions will be addressed by a team of researchers, and a capable Ph.D. student responding to this advertisement.
The Arctic charr (Salvelinus alpinus) of Lake Thingvallavatn are ideally suited for studies of the ecology and genetics of adaptive diversification: i) it is an extraordinarily well-characterised system, ii) it has young evolutionary history, iii) it has diverged into four morphs with distinct variation in life history characteristics, behaviour and trophic morphology, suggesting rapid adaptive diversification. This system thus represents an extremely compelling case of rapid adaptive differentiation.
However, to date, the system has been under-used to answer fundamental questions about the genetic basis of this diversification, due in large part to a lag in the development of genomic resources, and the long generation time. These issues have recently been overcome, and it is now possible to get at some long-outstanding questions.
The overall aim of this project is to answer fundamental questions about the genetic basis of this extraordinary case of rapid adaptive differentiation, by determining the number, genomic distribution, range of effect sizes on traits and evidence of selection of loci contributing to adaptive diversification. We will answer these questions by deploying a series of studies, using both classical genetic study designs (QTL mapping) of carefully constructed laboratory crosses, and modern population genomic analyses of field-collected specimens.