Relationships between ancestral plasticity and the evolutionary responses
For the positive ion mode, the ancestral plasticity in the pre-fish subpopulation correlated positively with the subsequent total evolution during the transition from pre-fish to high-fish (R = 0.28, P< 0.0001, Figure 6a). This pattern was driven by the evolution of plasticity (R = 0.43, P < 0.0001, Figure 6c), while the correlation of ancestral plasticity with constitutive evolution was negative (R = -0.28, P < 0.0001, Figure 6e). During the transition from high-fish to reduced-fish these patterns reversed: the correlations with ancestral plasticity were negative for both total evolution (R = -0.43, P < 0.0001, Figure 6b) and evolution of plasticity (R= -0.55, P < 0.0001, Figure 6d), and positive with constitutive evolution (R = 0.39, P< 0.0001, Figure 6f). These patterns were largely similar for the negative ion mode (see details in Supplementary Information).