Diversity of lung structure and airflow patterns in varanids
Different species of monitor lizards show an amazing amount of variation in of body size, habitat, ecological niche, and metabolic rate with a similar body plan. Their lung morphology is equally diverse, presenting an ideal system to investigate the relationship between lung design and life history traits in vertebrates. The final aspect of my dissertation work seeks to compare and contrast the pulmonary airflow patterns and lung morphologies of monitor lizards through CFD modeling of animals I collected during fieldwork in Australia.
Scaling of Locomotion in Varanid Lizards
Because the amount of force a muscle can produce depends on its cross-sectional area, which scales with body mass 2/3, animals should become relatively weaker at greater size. Larger mammals adjust with more erect postures, but varanid lizards keep the same sprawling posture over similar body size ranges. We built musculoskeletal models of 12 species of varanid ranging from 7g (V. brevicauda) to 37 kg Komodo dragons to investigate how lizards evolved to circumvent this biomechanical size limit. We found that varanids grow bigger than expected muscles, spread walking forces over a greater time,
Fluid Dynamics of Ventilation in Whales
I’m currently using CT scans and computational fluid dynamics (CFD) to investigate how lung biomechanics evolved with the marine environment in cetaceans. Whales & dolphin lungs are not only the largest in evolutionary history (!) but are subject to two interesting biomechanical challenges: they must either resist or recover from collapse due to external pressure while diving, while also ventilating effectively during extraordinarily short surface intervals. By comparing lungs from species that dive to different depths and use different ventilatory behaviours, undergraduate students and I (und
Axial biomechanics during walking and breathing
Ventilation and locomotion are inexorably linked in vertebrates because the axial skeleton (vertebrae, ribs, and sternum) plays a vital role in each activity. The design of the axial skeleton is a trade-off between these different roles, but because we don’t have good kinematic data during each behavior, the influence of each activity on the design of the bones and joints is unclear. This is because ribs and vertebrae during breathing and locomotion move in complex, three-dimensional patterns that are hard to measure using traditional techniques. XROMM (X-ray reconstruction of moving morpholog
