The Florida Anthropological Student Associations hosts weekly colloquia to showcase our graduate students’ and faculty’s research interests, to give them valuable opportunities to practice or refine their presentation techniques, and to help connect UF anthropologists.
Our next colloquium will be Friday, October 24 at 4pm in Turlington 1208:
JD Pampush
“The coevolution of circumperineal coloration and terrestriality”
Old World Monkeys (Cercopithecoidea) are unusual among primates for the high percentage of species exhibiting circumperineal coloration, as well as the large percentage of highly terrestrial species. Kingdon [1974, 1980] suggested that circumperineal skin coloration is correlated with terrestriality but this hypothesis has not been tested. From the literature we collected data on habitat use (terrestrial/arboreal) and circumperineal coloration (present/absent) for 78 species. Indeed, among the 78 species surveyed here, 75% of them fall into either the category of colored circumperineals with terrestrial lifestyle, or of uncolored circumperineals with arboreal lifestyle (Χ2(1)=19.550, P<0.001).
However, conventional statistical procedures assume all taxa are equally related—which is not usually the case in multispecies analyses—leading to higher rates of both Type I and II statistical errors. We performed Bayesian trait co-evolution analyses that show that models of dependent trait evolution are not significantly better than models assuming independent evolution of the two traits (log-likelihood ratio test P=0.396, BayesFactor=1). Bayesian nodal reconstructions of the cercopithecoid phylogeny indicate that relatively few trait transitions are needed to account for the distributions of the two traits. Further, chi-squared distributional tests show that sub-family affiliation (i.e. Cercopithecinae, Colobinae) is an accurate predictor of trait status. The discordance of the analyses may represent the results of a few different evolutionary scenarios, but ultimately circumperineal coloration seems very weakly linked to terrestrial ecology.