Importance of Considering the Plastic Expression of Phenotypes When Determining Evolutionary Relationships

The resurgence of interest in phenotypic plasticity has resulted in a wellspring of knowledge surrounding how the environment can influence evolutionary trajectory. However, the conversation surrounding it is often driven by similar narratives without accounting for other ways plasticity may shape evolutionary processes. Here, we attempt to broaden the discussion surrounding plasticity and evolution to better understand and interpret the evolution of phenotypic traits. We do this by examining four model systems that illustrate how studying plasticity through different lenses can shift evolutionary interpretations. Overall, we conclude that the multidimensional nature of phenotypic plasticity makes it a daunting task for evolutionary biologists to properly study. Luckily, ecologists have long been interested in understanding how complex environments shape organismal life history, and we argue that future research should take advantage of large ecological data sets when designing experiments meant to examine the evolution of plastic phenotypes.