Comparison of thermal developmental plasticity among seven recently sympatric <i>Anolis</i> species: insights into the evolution of reaction norms

Theory predicts that thermal developmental plasticity evolves in response to thermal heterogeneity, suggesting that plasticity may be an important trait for establishment in novel climates. However, few studies use multi-species comparisons to examine how plasticity evolves, meaning there is little empirical basis with which to examine key theoretical predictions. We estimate patterns of thermal developmental plasticity in morphological and performance traits for seven Anolis lizard species inhabiting South Florida, USA. We found interspecific differences as well as intraspecific variation in reaction norms across species. Neither temperature heterogeneity in present-day Florida nor historical temperature heterogeneity from the contemporary native ranges predicted reaction norm variation. Phylogeny and species identity typically predicted around 90-95% of reaction norm variation. Overall, these results suggest that thermal developmental plasticity in these traits exhibits variation that could be inconsistent with patterns expected under adaptive evolution to macroclimate. Examining the role of maternal nesting behavior and sampling of additional species can distinguish between neutral variation and selection toward multiple adaptive peaks. Our comparative study of thermal developmental plasticity in lizards provides new insight about macroevolutionary dynamics behind the evolution of developmental plasticity and the conditions under which adaptive plasticity is expected to evolve.