1Research Division, Harry S. Truman Memorial Veterans' Hospital, 2Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, 3Department of Internal Medicine, University of Missouri School of Medicine, 4Departments of Biological Sciences, Aerospace and Mechanical Engineering, and Anthropology, University of Notre Dame
Friday 2:45-3:00, Galleria South
The evolution and function of the human skull and feeding apparatus is intimately related to the mechanical demands imposed by food items. Primate dietary resources may often been seasonal, resulting in the consumption of non-preferred, difficult-to-process "fallback foods." Indeed, seasonality is invoked in ecological interpretations of fossil hominins (e.g. Paranthropus). Despite the temporal complexity of primate diets, little work exists related to the long-term impact of variability of dietary properties on craniofacial development. This study uses a well-established experimental species, the laboratory rat, to model primate skull growth as affected by temporal shifts in dietary properties. Four dietary cohorts (n=10/cohort) were raised from weaning to skeletal maturity. Two cohorts were fed a stable diet of either solid or powdered pellets. The other two cohorts were fed a variable diet of either solid/powdered pellets for the first half of the study, followed by a shift to the opposite diet. In-vivo microCT imaging was used to quantify ontogenetic changes in craniofacial morphology. Skeletal growth rates were assessed via fluorochrome labeling, and serological markers related to skeletal physiology were analyzed across the growth period. Results describe patterns of morphological variation and covariation in the mammalian craniofacial complex related to temporal dietary variability. This experimental approach emphasizes the capacity of laboratory studies to generate longitudinal data at multiple organismal levels which compliment observational and comparative studies of primates. An enhanced understanding of the impact of dietary composition on craniofacial variation is critical for evaluating ecomorphological reconstructions of feeding behavior in living and fossil primates.
The research was supported by a NSF DDRIG (1061368), the Wenner-Gren Foundation, and the American Society of Mammalogists. This material is the result of work supported with resources and the use of facilities at the Harry S. Truman Memorial Veteran’s Hospital, Columbia, MO.