The evolution of defenses and counter-defenses in plants and plant-feeding insects has frequently been postulated to increase the rate at which new species form, but yet there are few tests of whether this process causes speciation. Segraves will address this question by conducting manipulative experiments in a model plant-insect system where speciation is thought to be currently happening. The experiments will focus on the yucca moth Tegeticula yuccasella that eats seeds of seven different Yucca species. Genetic studies suggest that T. yuccasella may be differentiating into several new species that specialize on different yuccas. Segraves will determine whether moth populations are diverging from one another via adaptation to different yucca species, and whether these populations have evolved differences in preference and performance for different yuccas.
The scientific importance centers on increasing our understanding of the process by which new species are formed and, furthermore, the results may provide a general explanation for why some groups of organisms are so incredibly diverse. The broader impacts include mentoring for undergraduate and graduate students. A minority undergraduate fellowship will be offered, and students will both participate in the research and will conduct independent projects. The results will also be quickly disseminated through Segraves' website.
