Doctoral Dissertation Research: Musculoskeletal Craniofacial Evolution and Developmental Plasticity

University Of North Texas Health Science Center At Fort Worth, Fort Worth TX

Investigators

Abstract

This doctoral dissertation research project examines the effects of early weaning on the evolution of the muscles and skeletal tissue in the developing craniofacial complex. The modern human craniofacial complex has evolved to become smaller, with shorter midface and globular brain shape, characteristics linked to changes in diet and chewing. Previous investigations of this topic using bone in comparative and fossil materials have methodological limitations. Here, a novel combination of state-of-the-art imaging methods is used to analyze changes in bone and soft tissues during craniofacial development. The research has the potential to inform public health research on early life development. The project fosters student training and mentoring in STEM, and resulting data are disseminated through publications, presentations, and publicly available imaging databases. The project uses a gracilized comparative model to examine the influence of early and typical weaning on musculoskeletal craniofacial development. The specific aims of this project are to characterize the effects of (1) craniofacial gracilization and (2) early weaning on musculoskeletal performance, integration, and symmetry during the stages of oral motor skill development in early life. Previous research has focused on changes in skeletal tissue, primarily due to limitations in what is visible in a standard CT and what is preserved in the fossil record. A novel combination of contrast enhanced micro-computed tomography (micro-CT) methods is used in this project to analyze ontogenetic series of bone, muscle, and cartilage. This multilevel research design incorporates evolutionary, behavioral, morphological, and functional theories, allowing greater understanding of the impact of function and tissue interactions on the musculoskeletal development in the craniofacial complex. Furthermore, this project can improve our understanding of the form-function interrelationships in the craniofacial complex during highly plastic early life stages, with implications for behavioral adaptations and growth trajectories during human evolution. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.