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∞ )/(z0 –z∞ ), 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\(D_{t}=e^{{-\lambda}_{E}t}\).