Comparison of linear vs. exponential decay functions
A total of 290 experiments could be fitted with both piecewise regression and exponential decay models (Fig. S5). The remaining 18 could not be fitted with piecewise regression, which most frequently occurred because the minimum value of D (i.e. complete acclimation) was reached at the second observation, in which case multiple breakpoints can yield an identical fit. Of these 290 experiments, comparisons of their residual standard errors revealed that the data in 62% (n=180) of cases was best explained by the exponential decay model. Furthermore, superior fit by piecewise regressions (N = 110 experiments) was observed primarily in experiments where thermal tolerance was measured at relatively few time points following exposure of the study organisms to the new temperature (Fig. S6). Thus, for more comprehensive experiments (i.e. greater number of measurement points in time), the shape of the plasticity rate response is better described by an exponential decay function. Thus, in all further analyses we use the estimates of λE (Table S2).