David Vasseur a theoretical ecologist addressing fundamental questions in community ecology by means of developing of new mathematical theory, conducting simple lab-based experiments, and analyzing long-term data. The questions he address are motivated by a desire to mechanistically define the processes underlying population and community dynamics in aquatic systems. Research in his lab is divided among three main threads: i) The impact and maintenance of biodiversity in aquatic communities; ii) The causes and consequences of spatial population synchrony; and iii) Eco-evolutionary dynamics of competitive communities