Competition enables rapid adaptation to a warming range edge in a model plant community

Most predictions of whether populations will adapt to warming range edges ignore species interactions. We experimentally tested whether range-edge populations can adapt to warming within a competitive, model plant community (Lemna spp. and Spirodela polyrhiza duckweeds). Notably, we found that adaptation to warming range edges was possible only when populations evolved with interspecific competitors. Moreover, competitors enabled the evolution of both high-temperature tolerance and increased thermal performance breadth at the range edge, but not at the cooler range core. Our results reveal that competitors accelerate thermal adaptation when there is a shared evolutionary response to both competition and warming. Overall, we highlight the urgency of including community context in predicting future range shifts, showing that antagonistic interactions do not necessarily hinder adaptation to climate deterioration.