Functional Resurveys and Models Reveal the Interplay of Plasticity and Evolution of Pierid Butterflies in Response to Recent Climate Change

AbstractThe extent of contemporary evolution, which is mediated by interactions with plasticity, will be an important determinant of biological responses to climate change. We synthesize two functional resurvey projects that, coupled with mechanistic models, evaluate the interplay of plasticity and evolution of pierid butterfly larval (thermal sensitivity of feeding) and adult (wing melanization) traits over recent decades. We characterize thermal environments over the resurvey periods, which we interface with developmental and (historical, current, and hypothetical) thermal sensitivity traits to examine the implications of evolutionary changes. We find that the evolution of photoperiod-cued plasticity of wing melanization in California <i>Colias</i> is consistent with avoiding thermal stress during warming springs. Plasticity has not evolved for Colorado <i>Colias</i> populations, which have experienced stronger increases in climate means relative to extremes in recent decades. Evolution in Colorado <i>Colias</i> larvae has improved tolerance to warm extremes, whereas evolution in California <i>Colias</i> larvae has broadened thermal sensitivity, consistent with capitalizing on expanded seasonal thermal opportunity. Our models predict that Washington <i>Pieris</i> larvae have experienced shifts in the direction of selection to increase performance at warm temperatures. The research highlights the importance of evaluating changes in climate change exposure and sensitivity to understand interacting organismal responses.