Evolutionary niche shift in response to the mean salinity The mean salinity experienced during evolution had a highly significant effect on acclimated tolerance surfaces ( P < 2 × 10 –16 , likelihood‐ratio test—hereafter LRT—between models with vs. without effects of salinity mean).
Note that evolution of plasticity was only weakly significant when assay salinity was instead treated as a continuous variable ( P ‐value = 3.97 × 10 –2 for the interaction between S 1 and ρ 2 , ANOVA on 1000 imputed dataset), indicating that evolutionary changes in plasticity were poorly captured by changes in the slope of a linear reaction norm.