Testing the adaptive nature of convergent evolution: What are the functional consequences of divergence in metabolic genes in dwarf and normal whitefish populations?

Louis Bernatchez (Supervisor)

I am interested in understanding the genetic, biochemical and physiological mechanisms by which whole-animal performance traits, such as swimming performance, growth, and salinity tolerance, evolve in natural populations of animals. Most of my work to date has focused upon the mechanisms by which aerobic energy metabolism evolves and how differences in aerobic capacity may affect an animal’s capacity for locomotion – a performance trait that is predicted to influence survival and reproduction in many species.

I started in the Bernatchez Lab in January 2013 and will study the mechanisms by which differences in swimming activity have evolved among populations of lake whitefish (Coregonus clupeaformis). The lake whitefish is a member of the family Salmonidae that lives in rivers and lakes across North America. In a number of these lakes populations have diverged into ‘dwarf’ and ‘normal’ populations, or ecotypes. ‘Dwarf’ whitefish are smaller and younger at maturity, have a slower growth rate, feed on pelagic prey, and are more active swimmers than ‘normal’ whitefish. Prior work in the Bernatchez lab suggests that a number of performance traits, including swimming activity, display adaptive divergence among populations. In addition, the Bernatchez lab has identified hundreds of ‘candidate’ genes which may be contributing to adaptive differences in swimming capacity by combining population genomic studies with quantitative genetic analyses. Many of these candidate genes are found in core metabolic pathways, such as glycolysis, the citric acid cycle and the electron transport chain. While in the Bernatchez lab I hope to fill in some of the ‘gaps’ between divergence in genotype/gene expression and whole-animal swimming performance by testing to see which candidate metabolic genes are associated with differences in enzyme activity, biochemical pathway function, mitochondrial function, and muscle structure/function. These studies will help us to determine which candidate genes are most likely to contribute to adaptive phenotypic differences among populations of lake whitefish and further our understanding of how energy metabolism evolves in natural populations.

For links to my publications, go to:
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