Doctoral Dissertation Improvement: Challenging Assumptions of Dental Senescence Using a Primate Framework

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Extensive tooth wear may ablate functional features of the teeth, resulting in the end of the dentition's capacity to effectively break down food items (i.e., dental senescence). Such a loss of function is presumed to impede access to foods, resulting in reduced health status, reproductive success, and ability to survive. Nevertheless, how and at what point of wear teeth reach a senescent state is not yet well understood, nor is the extent to which dental senescence may affect individual health, nutrition and behavior. Natural selection should produce teeth which maintain the ability to fracture foods despite wear, and which only cease to function with severe wear. Individuals may compensate for dental impairment through behavioral mechanisms, or may be buffered against the impacts of wear by individual traits such as sex and/or social rank. This study, by doctoral student James Millette (University of Colorado), under supervision of Dr. Michelle Sauther, combines Geographic Information Systems-based dental topographic analysis of tooth form with individual behavioral-ecology, health and nutritional data to examine relationships between worn tooth morphology, food processing ability and behavior for ring-tailed lemurs (Lemur catta) of the Beza Mahafaly Special Reserve, Madagascar. This population demonstrates well-documented, varying levels of tooth wear and frequent tooth loss due to tamarind fruit consumption. The research will: 1) determine what level of dental wear is associated with reduced health and nutrition, 2) assess if behavioral mechanisms can buffer individuals against the effects of dental wear, and 3) examine whether individual traits such as rank and sex may impact such patterns. It also will provide valuable contextual information towards improved use of dental topographic analysis for assessing worn tooth functionality and its relation to behavior and nutrition within the primate fossil record. The conduct of the research will be complemented by enhancing international research collaborations, training of Malagasy students and educational outreach to local communities, and enhanced conservation of endangered habitats.