Andrea L. Sweigart
Department of Genetics
University of Georgia
Rapid evolution of postzygotic isolation via hybrid seed inviability in Mimulus
Abstract: The origin and maintenance of species depends on the evolution of reproductive isolation between diverging populations. Since Darwin, evolutionary biologists have strived to explain the emergence of species barriers and the coexistence of new species with related taxa. In this talk, I will focus on the evolution of hybrid seed inviability, a particularly common form of postzygotic isolation between closely related species of flowering plants, including in the genus Mimulus. We show that Mimulus hybrid seed inviability involves parent-of-origin effects and defects in the endosperm, which is a tissue critical for transferring maternal nutrients to the developing embryo that also serves as the primary tissue of genomic imprinting and an arena for parental conflict. I’ll discuss the implications of our work for understanding why postzygotic isolation evolves and how it contributes to the pattern and tempo of speciation.
Host: OEB Postdoctoral Fellows