The conservation of biodiversity requires an understanding not only of the factors that contribute to diversification and speciation but also of the population dynamics that allow species to remain distinct from one another. The PI will integrate a series of field and lab studies to identify how ecological, behavioral, and morphological factors enable hybridization but prevent widespread gene flow (introgression) between two species of woodrat, Neotoma fuscipes and N. macrotis. Specifically, the PI will identify where the barriers or filters to genetic introgression occur in the continuum of reproduction from spatial opportunity for interaction, to mate choice, gamete transfer, survivorship and reproductive success. The PI will incorporate aspects of this research into a high school outreach program. This program will train local high school biology teachers in molecular genetic techniques and collaborate with them to present these techniques to their students and integrate these activities into other components of the curriculum.
The proposed research and educational activities will train a continuum of individuals in the scientific method with special emphasis on molecular genetics and evolutionary processes. These individuals include high school students from the local Shoshone-Bannock tribe, undergraduates, PhD students, and biology teachers. The outreach program will be a model partnership between high schools and universities, cost-efficiently exposing students to modern molecular genetics and evolutionary research.
The conservation of biodiversity requires an understanding not only of the factors that contribute to diversification and speciation but also of the genetic and ecological interactions that allow species to remain distinct from one another. This award allowed the integration of a series of both field and lab studies to identify how ecological, behavioral, and morphological factors contribute to the occasional hybridization but overall lack of large-scale genetic introgression between woodrat species of the genus Neotoma. Our research through this award is establishing novel insights into multiple factors that determine the nature of ecological and genetic interactions at the boundaries between species. Specifically, we have discovered that diet specialization appears to underlie fine-scale spatial segregation that, in turn, limits hybridization by minimizing contact between the species. Accompanying these fine-scale shifts in diet, we find substantive morphological character displacement in cranial and dental traits and body size in zones of contact. Even when congeners have the opportunity to mate, our lab-based mate choice trials show that body size differentials and asymmetric aggression are strong determinants of mate choice in these hybrid zones. The body-size based asymmetries in mate choice we discovered in the lab are consistent with our field-based measures of asymmetric genetic introgression. Post-zygotic isolating factors we have discovered include reduced hybrid fitness, even one case of near complete male sterility. Thus far, these findings establish woodrats as a new model for research into novel arenas of the causes and consequences of particular reproductive isolating mechanisms between closely related species. During the time of this award we were able to provide research training for 13 undergraduate students, 6 graduate students, 3 postdoctoral associates, and 1 high school teacher. Of these 23 individuals 16 were women (70%). Three of these graduate students and 1 postdoctoral associate also received a high level of training in outreach education and high school teaching. We translated many of the genetic and evolutionary concepts central to our research program into a high school outreach program: "MOTR: Molecules On The Road". Through this program, we provided continuing education to 29 local high school biology teachers in genetics and evolution and collaborated with them to present these techniques and concepts to their students as well as to integrate these activities into other components of their curriculum. Through this award we provided our week-long, hands-on MOTR program to over 3,000 high school students. Students gained content knowledge in genetics and evolution, augmented their interest in science-related disciplines, and became more informed citizens by gaining an understanding of the genetic and evolutionary basis of biological diversity.
