Fig. 2.

Additive genetic variance (Va) across the environmental covariable (EC) for the four models. In the RN-L and RN-NL, the line connects the estimates of Va for each environment, whilst a smoothing spline was fitted to the estimates of Va across the EC in RR-2 and FA-2. RN-L: linear reaction norm; RN-NL: nonlinear reaction norm; RR-2: reduced-rank factor-analytic model with two common factors and zero specific genetic effects: FA-2: factor-analytic model with two common factors and specific genetic effects