This course offers an overview of ecological and evolutionary processes in natural populations, and how they can be studied with molecular methods. The course introduces fundamental concepts and principles in population and quantitative genetics, meta-genomics, and landscape ecology for a better understanding of the forces operating in natural systems. Students gain insight into the use of common molecular methods, their strengths and limitations for ecological coupling. Specific topics include detection of genetic variation within and among populations, speciation, selection and local adaptation, environmental DNA (eDNA) assays, and biological conservation. This course takes account of the technology breakthroughs achieved in recent years to give students a fully updated guide to the increasingly prevalent use of molecular data in ecological studies and environmental monitoring. The course consists of lectures, literature seminars, computer simulations, data exercises, and independent projects where students use empirical and simulation data to infer the distribution of genetic diversity at genome, population and community levels. Students will use DNA data to analyse and solve evolutionary and ecological problems.