Divergent phenotypes within a species, and especially sexual dimorphism, are common and allow species to differentially perform within their environment. Anolis lizards are a highly diverse clade of lizards that has been intensively studied for their exceptional ecomorphological radiation, and that shows varying levels of sexual dimorphism. Males generally have larger bodies and heads than females, allowing them to bite harder (beneficial both for feeding and male-male competition). As such, they have served as a model clade to better understand the mechanisms behind evolutionary diversification and adaptation. Still, several mechanistic aspects remain unexplained, such as the ones driving head shape dimorphism. In this project, we want to tackle three aspects of head shape dimorphism in Anolis. First, we want to test whether the degree of dimorphism is related to phylogeny, using a dataset of 130 anole species. Next, we want to determine whether food and testosterone manipulation, acting as a proxy for the selective drivers related to dietary
and male-male competition, affect head shape in both monomorphic and dimorphic species.
Subsequently, we will quantify in 3D the phenotypic responses to these manipulations in the cranial musculoskeletal system, the functional implications thereof, and whether the traits differ between sexes and species. With this approach, we hope to enhance our insights in the mechanisms driving the evolution of dimorphism in anoles.