9520694 Arnold Research will focus on how an individual's growth rate affects its age of maturation, its longevity and its offspring's survival. The investigators will also examine the costs to growth, costs associated with an individual's lifespan, the health of its offspring, and the environmental and genetic influences on variation among and within populations of Thamonophis elegans. Three approaches will be used: experiments in nature, experiments in the laboratory, and mathematical modeling. Ultimately, the answers to these research questions will contribute to an understanding of how the environment combines with an individual's genetic makeup to shape its growth, maturation, ald survival.