title: Teaching an old jaw new tricks: diet-induced plasticity in a model organism from weaning to adulthood.
abstract: Many organisms exhibit a decrease in the ability to modify their phenotypes in response to shifts in environmental conditions as they mature. Such age-dependent plasticity has important implications in a variety of evolutionary and ecological contexts, particularly with respect to understanding adaptive responses to heterogeneous environments. In this study, we used experimental diet manipulation to examine the life-history trajectory of plasticity in the feeding complex of a model organism, the white rabbit (Oryctolagus cuniculus). We demonstrate that, contrary to expectations derived from previous cross-sectional studies of skeletal plasticity, the jaws of weanlings and young adults exhibit similar increases in relative bone cross-sectional areas in response to the introduction of mechanically challenging foods into their diets. Furthermore, we present evidence that sensitivity to loading patterns persists well into adulthood in some regions of the masticatory apparatus in rabbits, indicating that there is an extended window of opportunity to respond to changes in dietary properties during an animal's life span. We conclude that certain aspects of the facial skeleton of rabbits, and perhaps mammals in general, are sensitive to environmental stimuli long after skeletal maturity is achieved, highlighting the importance of plasticity as a source of adaptive variation at later life-history stages.
authors.affiliation: Department of Anthropology, Southern Illinois University, Carbondale, IL 62901, USA.
authors.forename: Jeremiah E
authors.initials: JE
authors.lastname: Scott
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: McAbee
authors.affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Meghan M
authors.initials: MM
authors.lastname: Eastman
authors.affiliation: Departments of Biological Sciences, Aerospace and Mechanical Engineering, and Anthropology, University of Notre Dame, Notre Dame, IN 46556, USA Matthew.J.Ravosa.1@nd.edu.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Ravosa
mesh_terms: D000222:Adaptation, Physiological; D000821:Animal Feed; D000818:Animals; D001696:Biomechanical Phenomena; D016723:Bone Remodeling; D004032:Diet; D008297:Male; D008334:Mandible / Q000033:anatomy & histology* / Q000502:physiology; D008409:Mastication / Q000502:physiology*; D010641:Phenotype; D011817:Rabbits; D012886:Skull / Q000033:anatomy & histology
keywords: Adaptive plasticity; Developmental window; Growth; Mammal; Masticatory apparatus; Reaction norm