This project will examine the evolutionary processes responsible for flower-color divergence between populations of Phlox drummondii in areas with and without the closely related P. cuspidata. This divergence represents one of the best purported cases in plants of reproductive character displacement, in which two similar species with overlapping ranges evolve to minimize the amount of hybridization due to selection against gamete wastage. Combining both measures of individual fitness and analysis of patterns of molecular variation in the genes responsible for the flower-color change, the planned experiments will test whether this divergence satisfies a set of criteria for character displacement that have been developed over the past two decades, and thus determine whether this divergence truly constitutes character displacement. They will also test alternative explanations for the observed divergence, including local adaptation to an environmental factor unrelated to interaction with P. cuspidata.
An integral component of the research program outlined here is the teaching and training of students at a variety of educational levels. Funds are explicitly requested to support the training of one postdoctoral fellow and one graduate student. As in the past, undergraduates will be actively engaged in this research, both as Independent Study students during the academic year, and as summer research assistants. At the high school and undergraduate levels, women and minorities under-represented in science will be targeted for training in research.
