Plant Evolution Seminar
"Sibling Cooperation and Interparental Conflict in a Seed: How plant mothers, fathers, and siblings behave during the act of reproduction in flowering plants"
Differential expression of maternally and paternally derived alleles (imprinting) and consequent parent-of-origin effects are conspicuous in placental mammals and flowering plants, both of which have maternal care mediated by a novel filial transfer tissue (placenta and endosperm, respectively). In the case of flowering plants, seeds harbor a remarkable genetic and structural complexity, with five separate organismal and genetic entities (male gametophyte, female gametophyte, maternal sporophyte, embryo, and endosperm) interacting to ultimately produce a viable embryo. As such, the seed is potentially a site of conflict and cooperation among these organismal generations. This seminar will examine the evolutionary origin of a genetically biparental embryo-nourishing tissue (endosperm) in the common ancestor of flowering plants, as well as the consequent evolutionary and developmental effects of the insertion of a paternal genome into the “business” of maternal embryo-nourishing strategy. William (Ned) Friedman is an Evolutionary Biologist and Director of the Arnold Arboretum of Harvard University.