Development and evolution of plants. Current research focuses on the combined effects of genotype, environment, and ontogenetic history on the development and expression of plant phenotypes. Model systems include highly plastic sex expression in andromonoecious Solanum and highly constrained developmental phenomena associated with extreme preformation in alpine Polygonum and Caltha. These studies of plasticity and constraint form the basis for the concept of ontogenetic contingency, a set of developmental constructs that are crucial to understanding the complex determinants of plant phenotypes.

Diggle, P.K. and J.S. Miller. 2004. Architectural effects mimic floral sexual dimorphism in Solanum (Solanaceae). In press. American Journal of Botany.

Diggle, P.K. 2003. Architectural effects on floral form and function: a review. In: T. Stuessy, E. H