How Morphological and Physiological Mechanisms Affect the Performance of a Lizard (Podarcis muralis)

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Multiple factors influence an organism’s performance in a given environment, including morphology and physiology. These factors have been well studied on their own, but it is not clear how they interact to influence performance. Lizards are great model organisms because it is very easy to measure performance indicators, such as sprint speed. The intersection of morphology, physiology, and performance is of particular importance currently due to the insight it provides in the field of invasion biology. One aspect of our project investigates how different morphological characteristics affect an organism’s performance in different environments. In this project, we will examine many morphological metrics, including limb and tail length. We also will examine the micromorphology of a lizard toe. This portion of the project will use the Scanning Electron Microscope (SEM) to examine fine structures on a lizard toe pad and see if those structures affect performance. In the second aspect of our project, we will measure levels of stress and energy storage within lizard populations. We will collect blood samples to measure corticosterone, a stress indicator, triglyceride, a fat used for energy storage, and glucose, a simple sugar used in energy storage. To test our hypotheses, we will test sprint speed and endurance, both common indicators of performance. We constructed a racetrack for the individual lizards to traverse through while being tested over various conditions. Three substrates were chosen to simulate natural terrains. We’ve also added obstacles to test maneuverability. We will be researching these morphological and physiological aspects in lizards from across an elevational gradient in their native range in France as well as invasive populations within southern Ohio. Data from both invasive and native populations will be compared to see if there are significant changes in morphology and physiology that can be attributed to the environment.