Microsocm experiment during KOSMOS 2013 mesocosm experiment

Climate change challenges phytoplankton communities but evolutionary adaptation could mitigate potential impacts. Here, we tested whether adaptation to a stressor under laboratory conditions leads to equivalent fitness gains in a more natural environment. We found that fitness advantages that had evolved under laboratory conditions were masked by pleiotropic effects in natural plankton communities. Moreover, new genotypes with highly variable competitive abilities evolved on timescales significantly shorter than climate change.