75-6 Sat Jan 2 Locomotor spectra in basal vertebrates Struble, MK*; Gibb, AC; Northern Arizona University strublemikayla@gmail.com
The way an animal moves through its environment influences its success and reproductive fitness in its environment. As wildly as body plans, environment, evolutionary histories, and anatomy vary in these animals, so do too their locomotor patterns. Locomotion has been a difficult topic to study and historically has been tackled largely through the lens of identifying discrete locomotion patterns (gaits) which are biomechanically independent from other gaits a single animal may use. However, there is growing evidence that gaits are not as discrete as they are often treated, but rather exist on a kinematic spectrum where intermediate patterns exist. These intermediate patterns of locomotion, while utilized less often, provide an important framework for the evolutionary origins of the more commonly observed gaits and the adaptive pressures which helped shape them. To better understand how vertebrate gaits are related to one another, we investigated locomotor variation in leopard geckos, Eublepharis macularius, at a variety of speeds to test the relationship between inverted pendulum and spring-style gaits. Animals were filmed in dorsal and lateral view and 12 points along the animals’ bodies which documented broad-scale movements were hand digitized in over 200 individual strides to enable us to identify kinematic trends associated with speed. Although the biomechanical divide between inverted-pendulum and spring-style locomotion in mammals is often relatively distinct, the relationship between these patterns of locomotion in Eublepharis macularius are less distinct and biomechanical patterns shift more gradually between fast and slow speeds. These results support recent research identifying transitional gaits as kinematic links between attractor gaits, the biomechanically stable patterns of locomotion animals often gravitate towards.