Dr. Suzanne Edmands and Mr. Dennis Peterson of the University of Southern California are studying the early stages of speciation in the copepod Tigriopus californicus. Much of what we know of the genetics of speciation comes from a handful of model organisms (chiefly Drosophila) and focuses largely on sex chromosomes. T. californicus provides an alternative model that does not have morphologically distinguishable sex chromosomes. Work will focus on populations at the southern end of the species range where patterns of reproductive isolation are more severe and qualitatively different than those found in the rest of the species range. The project has three primary goals: 1) describe patterns of reproductive compatibility in southern populations, 2) use molecular phylogenies to reconstruct the evolutionary history of reproductive incompatibility, and 3) use molecular markers to determine regions of the genome contributing to reduced survival in first- and second-generation hybrids.
This research will have broader impacts through the career development and scientific training of both graduate and undergraduate students. It will contribute to our understanding of the process of speciation, arguably one of the most important yet least understood issues in biology. In addition, it focuses on the relationship between genetic divergence and reproductive compatibility, a subject of considerable importance to conservation and management.
