What have exotic plant invasions taught us over the past 20 years?

Invasive organisms have become a focal interest in ecology, owing not only to the tremendous destruction that they can cause, but also because we do not yet understand fully how they change from being minor components of their native communities to dominant components of invaded communities. Here, we discuss our perceptions of how the study of exotic plant species has contributed to the changing face of ecology over the past 20 years. Research on invasive organisms has promoted synthetic efforts between fields that have historically operated in isolation. Most importantly, the study of invasions has resulted in significant intellectual shifts in the way that old paradigms are perceived by ecologists and have led us into new and uncharted territory.