Biodiversity, commonly measured by species richness, is the cornerstone of ecological research. Another metric of biodiversity that may play a role in community function is species evenness. Species evenness measures the proportions of relative species abundance to community abundance. A meta-analysis of aquatic ecosystems has shown little to no correlation between species richness and species evenness, indicating that species evenness is an independent axis of biodiversity. Species evenness may play large roles in community properties such as persistence, resilience, and resistance in the face of environmental change.