Dr. Suzanne Edmands, University of Southern California
Abstract: Most progress in speciation genetics has come through work on model systems like Drosophila, with particular emphasis on the special role of sex chromosomes. A more comprehensive understanding will require studies of alternative systems with different sex determination mechanisms, such as those found in a wide variety of marine invertebrates, reptiles and plants. I will discuss results of breeding and molecular assays in the copepod Tigriopus californicus designed to test explicit predictions about the mechanics of speciation in the absence of sex chromosomes. This includes predictions concerning the number of incompatibilities, the level of conflict between nuclear and mitochondrial genes, the importance of sterility vs. viability problems and the cause of sex-specific hybrid dysfunction in the absence of sex chromosomes.