Currently, more evidence is accumulating that a variety of organism groups have the ability to rapidly adapt genetically to environmental stressors, which may have important ecoevolutionary implications for population demography and ecosystem functioning. However, the knowledge about if and to what extent microevolutionary adaptation may mediate the interactive effects of stressors is rare. Making use of rotifers (Brachionus calyciflorus), the aim of my project is to study how exposure of populations to a selection regime exerted by single stressors results in rapid evolutionary adaptation. Furthermore, we will investigate how populations with different evolutionary histories respond to the same or new combinations of related stressors.