Understanding macroevolutionary dynamics of trait evolution is an important endeavor in evolutionary biology. Ecological opportunity can liberate a trait as it diversifies through trait space, while genetic and selective constraints can limit diversification. While many studies have examined the dynamics of morphological traits, diverse morphological traits may yield the same or similar performance and as performance is often more proximately the target of selection, examining only morphology may give an incomplete understanding of evolutionary dynamics. Here we ask whether convergent evolution of pad-bearing lizards have followed similar evolutionary dynamics, or whether independent origins are accompanied by unique constraints and selective pressures over macroevolutionary time. We hypothesized that geckos and anoles each have unique evolutionary tempos and modes. Using performance data from 59 species, we modified Brownian Motion (BM) and Ornstein-Uhlenbeck (OU) models to account for repeated origins estimated using Bayesian ancestral state reconstructions. We discovered that adhesive performance in geckos evolved in a fashion consistent with Brownian Motion with a trend, whereas anoles evolved in bounded performance space consistent with more constrained evolution (an Ornstein-Uhlenbeck model). Our results suggest that convergent phenotypes can have quite distinctive evolutionary patterns, likely as a result of idiosyncratic constraints or ecological opportunities.

toe detachment angle trialsOur observed measurements of toe pad performance (toe detachment angle). These data include all of our observed trials, covering multiple individuals. The "individual" column represents the "names" of the individual animals tested and span multiple studies, hence there is no universal naming theme. Unique names relate to each individual. Note that some Anolis species are assigned a name of "NA" indicating that individual was not recored for that species. Following Hagey it al Journal of Experimental Biology 2016 219: 1603-1607; doi: 10.1242/jeb.129940, we fit each individual's set of trials to the weibull distribution, estimating a scale parameter with error for each individual. We then calculated a weighted species average using each individuals estimated scale parameter, weighted by the inverse of their error.toe pad presence absenceList of species and their toe pad assignment (presence or absence) used in our ancestral state reconstruciton