Grant: Discovery Grants Program - Individual

A central goal of modern evolutionary biology is to identify the genomic basis of adaptation and speciation. This will help us to understand how organisms have evolved in the past and how they might evolve in the future. The way that traits are encoded in the genome (their "genomic architecture") affects how they will evolve, as does the degree to which populations adapt to local environments and mix their genes with one another through mating and gene flow. To avoid losing important local adaptations in the face of gene flow, genomic architectures that "link" advantageous alleles together are thought to have evolved. We expect these types of architectures to be important in environments with high connectivity, such as the ocean. They might play an important role in adaptation to rapidly changing environmental conditions (e.g. harvesting, management actions, climate change) and they might play an important role in helping maintain species boundaries at sea. The proposed research program does not currently involve Indigenous communities or individuals. This project investigates the genomic architecture underlying adaptation in Atlantic cod, a highly ecologically, socio-economically, and culturally important species. Atlantic cod are widely distributed throughout the North Atlantic, where they show adaptations to local environments on remarkably small scales. The discovery of large chromosomal inversions in Atlantic cod, which might link advantageous alleles together in an "supergene", raises the question of what these variants do. We will conduct experiments to test for the effects of temperature, salinity, and food availability on the growth, survival, and gene expression of cod with different supergene types. We will also see if these potential supergenes produce a reproductive barrier between closely related cod ecotypes through a controlled experiment in a large artificial pond over several generations. Finally, we will use all available information about cod genetics and environmental responses to forecast how cod will respond to different harvesting, management, and climate change scenarios.