Postdoctoral Fellowship: EAR-PF: Evolution of tympanic hearing: Earth system drivers of sensory innovation in late Paleozoic terrestrial ecosystems

About This Grant

This NSF EAR Postdoctoral Fellowship award seeks to understand the origins of hearing in the Permian forerunners of today’s amphibians, reptiles, and mammals. During the late Paleozoic era, vertebrates colonized terrestrial ecosystems. Vertebrates evolved new sensory adaptations to navigate these new environments and acquire food. These adaptations included the ability to hear airborne sounds (tympanic hearing, using a ‘tympanum’ or eardrum). For example, several different groups of fossil vertebrates appear to independently evolve anatomical features related to tympanic hearing around the same time, more than 250 million years ago. However, the origins and drivers of these changes remain unknown. This work will investigate whether the origins of tympanic hearing are associated with changes in the position of Earth’s continents, environmental change, and the origins of sound production in insects. This project addresses the effects of geological processes and evolutionary dynamics on the biodiversity of early vertebrates. The project will broaden the impact of the research through creation of 3D models and engaging students at various levels in research, education, and outreach opportunities. Impedance matching, or tympanic, hearing evolved independently in the Permian ancestors of amphibians, mammals and reptiles, from a Carboniferous common ancestor that was not fully terrestrial. However, the abiotic and biotic drivers of these clustered origins of tympanic hearing remain unknown. This project aims to address this fundamental gap in our knowledge of sensory evolution and Earth processes by investigating these drivers and their effects on biodiversity during the Paleozoic using biomechanical, phylogenetic, and paleoecological approaches. This project will use interdisciplinary approaches such as biomechanical modeling to study the hearing performance of stem reptiles to evaluate the tympanic hearing capabilities of Carboniferous and Permian tetrapods. Preliminary results suggest that tympanic hearing originated in the middle Permian or earlier, during an interval of environmental upheaval of global change, which saw drastic continental processes and habitat restructuring. This fellowship will broaden the impact of the interdisciplinary research by training a new generation of scientists with strong anatomical, computational, and analytical expertise. 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.