Part of the capacity of a species to respond to environmental change depends on its evolutionary potential, which is rooted in the amount and structure of adaptive genetic variation. We previously showed that two coexisting and closely related fishes – three-spined and nine-spined stickleback – differ markedly in the strength and nature of local adaptation between brackish water and freshwater populations. This indicates that both species cope with landscape-level ecological heterogeneity in fundamentally different ways. We aim to improve our overall understanding of how adaptation is achieved in both species at the genetic, regulatory and epigenetic level.
