Abstract

The evolution of the phenotype has historically been studied by segregating it into categories, as traits within a category often exhibit close associations. However, individuals can be considered as integrated phenotypes, suggesting that their analysis may not correspond to an artificial categorization. Nonetheless, variations in the intensity or persistence of selective pressures over time can lead to mismatches in phenotypic evolution. Despite the potential for selective pressures to induce phenotypic changes, closely related species tend to exhibit similarities due to their common ancestry. In this study, we calculated and compared the phylogenetic signal of phenotypic traits of lizard species in the genus Sceloporus. We categorized these traits as either morphological or life-history traits, with a total of eight traits in each category. These traits include trunk length, limb length, head length, clutch size, hatchling length, age at first brood, and size at maturity. We found that the amount of phylogenetic signal varies across Sceloporus traits. The intensity of the phylogenetic signal was higher in traits derived from morphometric measurements, regardless of their category. The remaining traits exhibited notable variation, ranging from phylogenetically conserved traits such as reproductive mode to the absence of phylogenetic signal, as seen in relative clutch mass. Furthermore, we observed that traits possibly influenced by the same evolutionary mechanism exhibit similar amount of phylogenetic signal, regardless of category. Finally, we discuss the potential implications of phylogenetic signal in the evolution of Sceloporus phenotypes.