CAREER: Biomechanics and Functional Ecology of Adhesive Gecko Toe Pads and Surface Texture

Mississippi University For Women, Columbus MS

Investigators

Abstract

The process of evolution often discovers similar solutions in different animals. For example, birds, bats, and pterosaurs all developed wings by modifying their front limbs. Hagey’s NSF CAREER award titled: Biomechanics and Functional Ecology of Adhesive Gecko Toe Pads and Surface Texture will study a similar process, the repeated evolution of adhesive toe pads in gecko lizards. Different groups of geckos independently evolved similar toe pads. A better understanding of how gecko toe pads work and evolved will allow for better understanding of why evolution sometimes finds the same solutions in different animals. Hagey’s project will also help scientists develop synthetic adhesives like those of geckos. Lastly Hagey will be observing wild geckos in Morocco and Tanzania, sharing knowledge and learning from local scientists. Knowing what kinds of trees and rocks geckos use is necessary for scientists to protect or restore habitats in a way that can be home for as many species as possible. Hagey’s NSF project will combine research tools from biology and engineering, working with engineering students to develop 3D models of gecko toe pads and computer simulations of how they work. Hagey’s project will include students from Mississippi University for Women and Mississippi State University. The experience students gain as a part of Hagey’s project will help them pursue future careers in science and engineering. This project is jointly funded by the Physiological Mechanisms and Biomechanics program of the Division of Integrative Organismal Systems and the Established Program to Stimulate Competitive Research (EPSCoR). Hagey’s NSF CAREER award will investigate patterns of repeated evolution, combining custom biomechanical simulations and field-based observations to investigate the functional ecology and adaptive history of gecko toe pads. Biomechanical simulations include the development of 3D imaging techniques and custom finite element simulations, incorporating intermolecular forces, to directly connect adhesive morphology and adhesive performance. With this approach, Hagey’s team will investigate the influence of surface texture on the performance of gecko toe pads, allowing insight into how particular morphologies perform on specific surfaces. These functional morphology predictions will be evaluated using observations from the field. Hagey’s fieldwork will focus on two scansorial communities of geckos that contain examples of recently evolved incipient toe pad morphologies. Projects will correlate microhabitat variables with adhesive morphology and performance, fostering additional hypotheses to be tested using Hagey’s biomechanical simulations. Measurements of niche partitioning in communities with recently evolved toe pads will also allow Hagey to identify possible microhabitat characteristics that lead to the evolution of adhesive pads. Broader impacts of Hagey’s project include the development of an interactive hands-on museum exhibit with a functional 3D printed lizard adhesive toe pad, an annual weeklong summer STEM course for middle school children, and a research methods course for Mississippi University for Women students. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.