Collaborative Research: Evolution of the hyoid, pharynx and swallowing biomechanics in mammals

Heritage College of Osteopathic Medicine earned a three-year, NSF-funded research program investigating the evolution, anatomy and biomechanics of swallowing in mammals. Building on a laboratory focus on the physiology and biomechanics of feeding, Williams and collaborators will examine the hyoid and pharynx—structures central to the act of swallowing—to understand how variation in their form and configuration across mammalian species influences swallowing performance and evolutionary diversification. The hyoid, a small bone located at the base of the tongue and anchored by ligaments and muscles to the skull, plays a pivotal role in propelling food and liquids safely into the esophagus. Across mammals, hyoid shape, structure, and position vary widely, yet the functional reasons for this variation remain unclear.

This project aims to trace hyoid diversity phylogenetically and biomechanically, testing hypotheses about how hyoid architecture and associated musculature enable powered swallowing and accommodate different feeding ecologies, body sizes, and life histories. By integrating comparative anatomy, biomechanics, and evolutionary context, the investigators will analyze multiple mammalian taxa to identify patterns linking form and function in the oropharyngeal region. Beyond evolutionary questions, the research has direct translational relevance: several of the animal models included in the study serve as models for human swallowing disorders. Improved mechanistic understanding of how musculoskeletal structures and soft tissues coordinate during swallowing can illuminate causes of dysphagia associated with neurodegenerative and musculoskeletal conditions, such as Parkinson’s disease, and inform development of clinical treatments and intervention strategies.

The project also includes an educational outreach component that will translate research findings into STEM learning modules for elementary and middle school teachers. These modules will introduce students to basic concepts in anatomy, evolution, and trait diversity, leveraging museum and classroom resources to make the science accessible to K–12 audiences. The modules will be distributed through the OHIO Museum Complex, a regional resource focused on K–12 science education, thereby extending the project’s impact beyond academia into community and educational settings. Over the course of the grant, the laboratory team will expand comparative datasets, refine biomechanical models of swallowing and disseminate both scientific insights and curricular materials. The combined research and outreach plan aims to deepen scientific understanding of a vital physiological process—swallowing—while linking evolutionary morphology to health-relevant questions and fostering science education at the K–12 level.