Genomic responses to rapid environmental change

Stickleback are small fish, common in oceans across the northern hemisphere. They have colonised and adapted to freshwater innumerable times, establishing populations in lakes and rivers after the end of the last ice age. Changes in the DNA of stickleback that have accrued during this 10,000 years of long-term adaptation to freshwater have been exceptionally well documented. It is also well known that stickleback can adapt very quickly to freshwater, with significant changes in phenotype, and even some genes, occurring within one to ten years. However, the patterns of short-term changes in the DNA and its expression are poorly understood. In this project we examine the process of rapid adaptation to short term environmental change. We do so by making replicated introductions of marine or marine X freshwater three-spined stickleback into freshwater ponds, and sampling genotypes from each pond on an annual basis to study genomic adaptation to this novel environment.