Lucas Eckert
Project
Testing for Real-Time Parallel Evolution in Threespine SticklebackSpecies are expected to attempt to respond to climate change through adaptive evolution, but the predictability of this process remains unclear, hindering our ability to protect biodiversity. While natural selection is thought to be a deterministic (predictable) process, ecological and genetic contingencies can alter the trajectory of evolution away from the expected outcome. Parallel evolution (the phenomenon of populations independently evolving similar phenotypic or genotypic changes in response to similar pressures) is cited as evidence for the deterministic nature of adaptation, but while examples of parallel evolution are compelling, it is not clear whether these case studies are the exception or the rule. Unfortunately, previous studies lack the real-time data necessary to fully investigate the relative importance of contingency and determinism in dictating evolutionary trajectories. I propose to fill this gap by testing for real-time parallel evolution in a large-scale natural experiment using threespine stickleback (Gasterosteus aculeatus), a model organism for evolutionary genomics. In 2019, stickleback populations were used to colonize nine fishless lakes in the Kenai Peninsula, Alaska. I will track the evolutionary changes that have occurred since colonization on both the phenotypic and genomic levels and determine the extent to which these changes occurred in parallel between populations, effectively quantifying the predictability of the process. Determining the predictability of evolution is not only a fundamental question in biology but may prove instrumental in understanding species responses to climate change and protecting biodiversity.
