Project
Examining parallel and non-parallel components of lake-stream stickleback divergence on Haida GwaiiRecent studies on the threespine stickleback (Gasterosteus aculeatus) system have significantly advanced our knowledge of evolutionary processes, particularly parapatric divergence. For instance, we now have a clearer understanding of the effect of gene flow and intrinsic environment components on the degree and direction of population divergence. Still, new examples of parapatric divergence are needed to clarify and better current knowledge and to make discoveries. Past studies on two lake-stream pairs of the archipelago of Haida Gwaii, BC, Canada, suggest that the archipelago has high potential to lead to advances. Indeed, this archipelago is considered one of the more striking examples of evolutionary radiation of vertebrates in the temperate latitudes, which implies that lake-stream pairs on Haida Gwaii might display unique patterns only found on Haida Gwaii. Yet, insufficient parapatric divergence research has been done in Haida Gwaii to confirm this statement from a parapatric divergence point of view since most pairs are yet to be studied. Here, we aim to assess Haida Gwaii’s potential for parapatric divergence research by sampling new lake-stream pairs and highlighting new cases of parapatric divergence to compare Haida Gwaii to other areas of the stickleback range. We are using samples from 15 lake-stream pairs that include the two previously studied lake-stream pairs (Mayer and Drizzle). We use morphological traits to identify divergence in traits within and between pairs, geometric morphometric analyses to quantify body shape divergence and sequencing (Pool-Seq) to compare the genome of each population. Preliminary results suggest that the lake-stream pairs of Haida Gwaii display high potential for research on parapatric divergence that could lead to advances in our understanding of this evolutionary process.
