Simons, EvanQuintanilla, AndreaSimons, EvanFrost, Stephen2020-08-112020-08-112020https://hdl.handle.net/1794/25513Project files are comprised of 1 page pdf and presentation recording in mp4 format.Primate cranial shape in relation to age, sex and taxonomy is a growing topic of research, with large-bodied Old World monkeys being among the most studied using geometric morphometrics (GM) and used as models for human cranial shape variation. Ontogenetic changes to skull shape from juveniles to adults are well studied, but those that occur during adulthood are less well known: a twenty-year old is still an adult, but their skull could differ in shape compared to that of a sixty-year old. In this project, we used GM and multivariate analyses to observe changes of cranial shape that occur with post-adult aging. Forty-five 3D landmarks were collected with a Microscribe 3DX digitizer on a sample of 347 wild-collected baboon (Genus Papio) crania, and subjected to generalized Procrustes analysis using the Geomorph package in Rstudio; this superimposes the data and standardizes geometric size, but leaves shape differences. The resulting Procrustes shape coordinates were adjusted for size and sex with multivariate regression analysis to mitigate the effects of allometry and dimorphism. These adjusted coordinates were then regressed against upper third molar wear stage as a proxy for age, using multivariate tests for significance. Principal components analysis was used to summarize the resulting shape space. Results demonstrated that there is a significant effect of molar wear stage on cranial shape, even after accounting for size and sex differences, but it is a subtle effect that accounts for approximately 1% of shape variance. In the future, we will investigate causes of this shape change.video/mp4application/pdfen-USCreative Commons CC0Geometric MorphometricsPrimatologyMorphologyOntogenyDentitionPresentation0000-0003-2927-4286