Understanding the processes that create, maintain and alter biological diversity is a primary goal of evolutionary biology. This is becoming even more important given the rapid changes in biodiversity due to human activities. Although there is a growing recognition that ecological and evolutionary processes can interact on similar time scales and jointly influence biodiversity, knowledge of these integrated processes is still fragmented. In this project, we quantify decades of phenotypic evolution of stickleback in Lake Myvatn in relation to temporal and spatial variation in both abiotic (e.g. temperature variation arising from inflowing hot springs) and biotic (e.g. midge emergence dynamics) environmental conditions.