Calculating rates of plasticity
Rates of plasticity were calculated according to the approach outlined by Burton et al. (2022). Thus, for each observation of temperature tolerance at times t we first calculated the proportion of the full plastic response that remained to be achieved,Dt , as (zt -z )/(z0z ), wherez0 is the first measurement of the phenotype (typically measured prior to the onset of acclimation), zt is the phenotype after acclimating for a time period t (for the current study twas standardized to unit h), and z is the fully adjusted phenotype. In theory, z is the final measurement of thermal tolerance. However, given measurement noise this may not be the case. Thus, we defined z as the maximum (for acclimation to higher temperature) or minimum (for acclimation to lower temperature) value for a given measurement of tolerance observed. For each experiment, we considered two potential responses in plasticity of thermal tolerance. First,Dt may have a value of 1 at t = 0 (first measurement) and decline linearly with time with a rateλL given by λL = (1-Dt )/t until it reaches 0, after which it will be constant. Alternatively, Dt may have a value of 1 at t = 0 and decline as an exponential decay function towards 0 with rate λE , such that\(D_{t}=e^{{-\lambda}_{E}t}\).