Lauren Gonzales is a PhD candidate from Duke University. She was awarded a Leakey Foundation research grant in the fall of 2013 for her project entitled “Intraspecific variation in semicircular canal morphology in platyrrhine monkeys.”
Understanding the functional relationship between locomotion and the morphology of the semicircular canals is an important adjunct for the reconstruction of locomotor adaptations of extinct primates. It may also be the only source of data when limb bones are unknown or fragmentary. Unfortunately, data from large populations is not available for most primate groups, and functional interpretations for extinct species may be confounded by factors such as brain-size/canal shape interactions and intraspecific variation resulting from differences in ontogenetic trajectories. The goal of my dissertation is to document intra vs interspecific variation in semicircular canal dimensions associated functionally with locomotion and to elucidate the roles of selection and constraints influencing inner ear structure.
Transparent Alouatta side view
My work concentrates on focal species matched for relatedness, body size, locomotion (defined as habitually fast or habitually slow), and components of relative brain size. To this end, I have proposed several research foci: 1. Provide data on the levels of variation found in canal radius of curvature and canal orthogonality in a large population of strepsirrhines and platyrrhines. 2. Evaluate the relative contributions of locomotor agility, brain size and body size to semicircular canal shape and size. This research will amplify and extend our knowledge of vestibular shape variation and provide the foundation from which more effective predictive models can be built and interpreted. Ultimately, a clearer understanding of intraspecific variation in canal morphology allows for a more accurate interpretation of fossil species.