Our research seeks to reconstruct the recent history of adaptive molecular variation in plant systems. In other terms, we aim at dissecting the molecular mechanisms of Darwinian evolution in complex natural systems. We work with the weedy annual and model plant species Arabidopsis thaliana and its close relatives A. lyrata and A. halleri as well as its distant relative Arabis nemorensis. Our work focuses on understanding links between life history strategies and fitness. We further intend to develop new methods to track the action of natural selection at the molecular level.