Rapid and repeated evolution of increased competitive ability in a global invader.

Non-native Erigeron canadensis populations evolve increased competitive ability independently in two of four genetic clusters, enhancing invasion success under diverse conditions.

• Why it matters: Understanding whether rapid evolution of competitive traits is a widespread response in invasive species is crucial for predicting ecological impacts and managing invasions effectively.
• What they did: The study involved genotyping 265 populations and conducting a large-scale glasshouse experiment testing competition and drought effects, revealing significant competitive advantages in non-native populations.
• The result: The repeated evolution of competitive ability, especially during interspecific interactions, suggests that rapid adaptation can reshape species interactions and bolster invasiveness, even amid future drought stress.