Dr. Christina M. Sluka

Urbanization is one of the fastest and most extreme processes creating novel conditions and affecting persistence of animals in the Anthropocene. We investigated craniodental morphological change in raccoons (Procyon lotor) with specimens collected across the continental USA based on three hypotheses of urban morphological change. Using modeling of linear measures, as well as 3D geometric analysis, and stable isotope diet estimation, we found that the occlusal area of the first molars and mandibular fourth premolar in addition to the cranial vault shape were most responsive to urbanization. Rostral shape showed limited variation across the urban and ecological gradients. Some structures, while variable, did not respond to any of the predictors tested. Our results provide the highest support to the self-domestication hypothesis (SDH), although multiple other pressures co-occur including effects of sex, age, individual size, and geography. Our results also suggest that some craniodental structures may be evolutionarily fixed and promote the raccoon’s generalist ecology.