For my PhD, I am exploring patterns and predictability of adaptation in threespine stickleback (Gasterosteus aculeatus). Using a large-scale field experiment in Alaska, I am tracking the evolutionary trajectories of these populations following colonization of a new environment across multiple levels.
In 2019, we colonized nine fishless lakes in the Kenai Peninsula of Alaska with stickleback from a pool of nearby populations. These lakes were poisoned with rotenone in 2018 to get rid of invasive northern pike which had ravaged the local fish populations. In collaboration with the Alaska Department of Fish and Game, we introduced threespine stickleback into these lakes, a native species of ecological importance. These introductions provide the perfect opportunity to watch the process of adaptation in real-time.
On the population level, I am exploring the factors that determine the success of a source population once exposed to a new environment. Primarily, I will be tested if increased similarity between your old and new environment makes you more likely to survive and thrive.
On the phenotypic level, I am tracking how the morphology of fish within these populations is changing over time. As well, I am seeing how parallel these changes are among populations and if the environment of the lake can predict the direction and magnitude of phenotypic response.
On the genomic level, I am determining the genetic basis of the observed morphological variation and how changes at these loci correspond to changes in morphology. This should shed light on the complex relationship between phenotypic patterns and the underlying genetic variation.
Finally, on the epigenetic level, I am exploring the role of methylation in response to this colonization event. DNA methylation can play a crucial role in the response to environmental changes by altering gene expression. By looking for patterns of methylation between populations, we can tell which genes are involved in this response, and how predictable that response may be.