Data from: No geographic variation in thermoregulatory color plasticity and limited variation in heat-avoidance behavior in Battus philenor caterpillars
Nielsen, Matthew E. (2017), Data from: No geographic variation in thermoregulatory color plasticity and limited variation in heat-avoidance behavior in Battus philenor caterpillars, Dryad, Dataset, https://doi.org/10.5061/dryad.5p2v8
Phenotypic plasticity can help organisms cope with variation in their current environment, including temperature variation, but not all environments are equally variable. In the least variable or extreme environments, plasticity may no longer be used. In this case, the plasticity could be lost all together, or it could persist with either the same or an altered reaction norm, depending on factors such as the plasticity's costs. In the pipevine swallowtail caterpillar (Battus philenor), I tested for changes in two forms of heat-avoidance plasticity, color change and refuge-seeking behavior, across the species’ range in the United states, including the cooler eastern parts of its range where color change has not been observed and is unlikely to be needed. I found that both heat-avoidance behavior and color change persisted in all surveyed populations. Indeed, the reaction norm for color change remained nearly unaltered, while the threshold for refuge-seeking only changed slightly across populations. These results suggest that the costs of these plastic traits are low enough for them to be maintained by whatever minimal gene flow the population receives. I show that plasticity can be maintained unaltered in populations where it is not used and discuss the potential consequences of this persistence for both the ecology and evolution of plasticity.