Princeton Vaughn and Dr. Eric Gangloff
An organism’s morphology (how its body is shaped) affects its performance (how effectively it carries out tasks like sprinting and climbing). This relationship can change in different contexts. Therefore, we might expect to find trade-offs whereby beneficial morphology in one environment can be detrimental in another environment. Understanding how morphology affects performance in novel environments is necessary to understand how invaders can be successful. We tested this relationship in the common wall lizard (Podarcis muralis) by measuring their sprint speed under a variety of conditions with a full-factorial design of substrate type (cork bark, artificial grass, and sandpaper), sprinting elevation (level, incline), and obstacles (presence, absence). We also measured the size of various body dimensions important for locomotion including tail length and limb dimensions. We analyzed these data to answer three questions, (1) on what condition do lizards best perform? (2) Are there any within individual performance trade-offs (do lizards who run faster on one substrate run slower on another)? (3) How does morphology affect sprint performance? Our results show that lizards perform best on artificial grass without obstacles, but on cork with obstacles. Surprisingly, lizards consistently perform better on an incline compared to a flat track on all substrates. We also found significant negative correlations between sandpaper and the other two substrates. Larger lizards ran faster than smaller lizards, but only without obstacles. This research will allow us to see how these lizards can respond to different environments and provide insight into how invasive species colonize novel environments.
Please watch this video presentation for a more complete understanding of our experiment and the theory behind it.