Origin of the Fittest and Survival of the Fittest: Relating Female Gametophyte Development to Endosperm Genetics

Abstract

For more than a century, most biologists have viewed the structural diversity of angiosperm female gametophytes as trivial variants of the reproductive process. However, analysis of variation among angiosperm female gametophytes from an evolutionary developmental perspective can provide new insights into patterns of reproductive innovation and evolution among flowering plants. The key is to link the developmental and structural diversity of angiosperm female gametophytes to evolutionary innovations (perhaps even adaptations) associated with endosperm genetics and ploidy. Selection has been hypothesized to favor endosperms with higher ploidy, higher heterozygosity, higher maternal‐to‐paternal genome ratios, and reduced opportunity for genetic (interparental and/or parent‐offspring) conflict. We evaluate these hypotheses for the seven basic genetic types of endosperm known among flowering plants and interpret their relative importance when mating system is considered. We demonstrate that variation in female...