Surprisingly little is known of the mechanisms that generate and preserve the Earth's tremendous biological diversity at the level of species. The goal of this research is to measure the relative contributions of adaptation and chance to the initiation of new species using an annual plant, Diodia teres, as a model system. The degree of divergence due to adaptation to different environments and the amount of genetic differentiation due to chance alone will be measured for a set of six populations of an annual plant. The degree of reproductive isolation among populations, a measure of the extent to which they constitute different incipient species, will also be measured. Analysis of the relationship of adaptive differentiation and chance differentiation among populations to the amount of reproductive isolation will be used to quantify the contribution of each process towards the formation of new species.
The results of this research will contribute to our ability to predict the consequences of anthropogenic disruptions such as habitat fragmentation and of longer-term processes such as global warming for the process of the generation of new species. This award will also contribute to the training of a graduate student who is a member of a group that is underrepresented in the sciences.
