In most plants and animals, males and females differ in size, shape, or color because natural selection drives the sexes in different directions. The evolution of this dimorphism is constrained by the mixing of genes among males and females during mating known as between-class gene flow. This work investigates the effects of between-class gene flow in a plant Silene vulgaris, in which individuals are either hermaphrodite or female. In species with such complex mating systems, the rates of between-class gene flow vary among populations, allowing their effects to be more easily detected. Using genetic markers, this work will estimate the strength of natural selection in hermaphrodites and females, as well as the patterns of gene flow among hermaphrodites and females for multiple populations. These estimates will be combined with estimates of heritability to determine if between-class gene flow limits the evolution of differences between sexes.
This work will test the importance of between-class gene flow as a factor affecting adaptation in natural systems. The understanding of this process will inform strategies for artificial selection of agriculturally important species such as cattle (Bos primigenius), in which males and females have different desired traits, and species with complex mating systems, such as maize (Zea mays). Finally, this work directly supports the training of a doctoral student as a researcher and mentor and provides opportunities for undergraduate students to engage in research in quantitative genetics and molecular ecology.
