PhD Research

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 how these populations respond following colonization of  a new environment across multiple levels: from population dynamics, to phenotypic changes, to the underlying genetics.

In 2019, we colonized nine fishless lakes in the Kenai Peninsula of Alaska with stickleback from a pool of nearby populations. These lakes were treated 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. Check out the project website for more detail!

Also on the population level, I am taking this opportunity to explore the potential for progress towards ecological speciation between these two ecotypes and among these divergent populations.  I'll be doing this by looking at patterns of mating and admixture when multiple populations are introduced to the same lake. Are two fish of the same source population or ecotype more likely to mate with eachother than with someone of a different population/ecotype?

On the phenotypic level, I am tracking how the morphology of fish within these populations is changing over time, with these phenotypic changes representing both plasticity and evolutionary change. I will explore how parallel these changes are among populations and if the environment of the lake can predict the direction and magnitude of phenotypic response.

To begin to disentangle plasticity from adaptive evolution, I am determining the genetic basis of the observed morphological variation and changes. I will explore the genes that are associated with morphology and determine if the same genes are always associated with the same morphological changes, which will shed light on the complex genetic basis of adaptation.