Figure 2.

Effect sizes for alewife presence and trait change (divergence between anadromous and landlocked forms) from the experiment reported in Palkovacs and Post (2009). Alewife presence had larger effects on zooplankton biomass, whereas trait change had larger effects on mean zooplankton length for cladocerans and copepods, zooplankton species richness, and zooplankton diversity. These results suggest that anthropogenic trait change can have ecological effects on par with those of traditional ecological drivers, such as species presence and diversity.