With this research project, the PI seeks to understand the ecological, physiological, and genetic health measures that determine a population's fate. This research will result in an answer to the question why some populations thrive and grow, whereas others, in similar habitats, wither and ultimately go extinct. Another goal of this research is to utilize collections of frozen tissue collected over the past two decades to test for physiological health and genetic state of the individuals that comprise both healthy and declining populations. Ultimately, this research will result in a better predictive power about how animals move across their landscapes, utilize resources, and persist in the wild by taking into consideration the physiological and genetic signatures of individuals. The PI's undertakings will involve many high school and college students, as well as graduate students working towards their master-of-science or doctorate degrees.
Sweeping anthropogenic changes to environmental landscapes in the late 20th and early 21st centuries pose urgent challenges to organisms and their populations. Potential organismal responses to unsuitable and disintegrating habitats are to move, perish, acclimate ecologically, or adapt evolutionarily. Predicting among these population outcomes requires long-term studies in which species, demography, physiology, ecology, and genetic variability have been monitored before as well as during a period of habitat change. The PIs will couple long-term spatial and temporal data, spanning 1976 to present, on variation in physiological processes and life-history traits with genetic markers of population health to develop a framework for integrating physiology, genetics, and demography in predicting responses of populations facing habitat degradation. Furthermore they will couple measures of individual state variables (physiological plasticity, genotype, and fitness measures) to link individual-level states and heterogeneity among individuals to population-level demography. They will accomplish these goals of measuring longterm heath indices by mining or longterm tissue and DNA collections on replicate populations of garter snakes inhabiting the northeastern Sierra Nevada mountain range. To accomplish the synthetic goals, mathematical models with structural equation modeling and additional modeling approaches will be developed and utilized. This will result in a fully-linked model of the relationships among physiological and genetic variation, organismal life-history variation, and environmental variation.
