Understanding the molecular changes by which organisms adapt to their environments is a central theme of evolutionary biology. With the pace of environmental change quickening due to loss of habitat worldwide and accelerated global climate change, and the exposure of humans to previously unencountered pathogens (such as HIV), the processes of molecular evolution are key to our survival and the survival of many organisms on this planet.
This project will study the evolution of resistance to scorpion venom, in ion channels, of desert-dwelling grasshopper mice. Grasshopper mice prey on scorpions and, when stung, show no adverse effects to scorpion venoms that cause intense pain and/or kill other mammals their size. This proposal will focus on the molecular evolution of a sodium ion-channel gene that is expressed in pain-sensing neurons. Species and individual differences in pain sensitivity of grasshopper mice to scorpion venom will be studied on the genetic, physiological and molecular levels, and the consequences of these differences for the behavior and ecology of these unique mice will be determined. This project will also gain further understanding of how the nervous system processes painful stimuli.
This project represents a partnership between the University of Texas, a major research university, and Sam Houston State University, a non-PhD granting institution with many students from underrepresented groups. We will recruit undergraduates from both institutions, focusing on underrepresented minorities. Additionally, this project will produce a videotape on co-evolution with the bark scorpion-grasshopper mouse system as an example of how animals make a living in the harsh desert environment. The videotape will be featured in an exhibit at the Texas Memorial Museum. Finally, our previous work on this system has already attracted interest from the media and there are plans for it to be highlighted in a National Geographic television special.