The document discusses how local adaptation and migration evolve in populations living in environments where selection fluctuates over time and space. It presents a model where migration is shown to increase local adaptation by reducing the lag time for adaptation, though more individuals are temporarily maladapted. The model finds an intermediate migration rate maximizes local adaptation across different environment shapes. It also shows migration can be selected for due to linkage disequilibrium dynamics, with the evolutionarily stable migration rate depending on the selection parameters. The document concludes migration may be an adaptive strategy for fluctuating environments.