Hybrid Seed Inviability and the Evolution of Endosperm Development in Mimulus – The endosperm is the starch- and/or protein-rich tissue within the seed. It is estimated that 67% of the calories of the human diet are derived from the endosperm of agricultural varieties (mostly grains). In addition to its agricultural importance, the study of embryo and endosperm development is of interest to both developmental biologists and evolutionary biologists. The parental conflict theory is an evolutionary theory that predicts that genes supporting endosperm and embryo development will be subject to imprinting and parent-of-origin effects. Furthermore, the rapid evolution of genes that function in the regulation of parental conflict has been proposed to act as a reproductive isolation mechanism and thus may support speciation events. In this collaboration with Dr. John Willis in the Dept. of Biology at Duke University, we are examining embryo and endosperm developmental defects resulting from incompatible inter-specific crosses between Mimulus species. We expect these studies will illuminate developmental, molecular and evolutionary mechanisms of reproductive isolation and speciation, as well as mechanisms of endosperm development.