Collaborative Research: Unraveling the Dynamics of Mating System Evolution in the Tribe Collinsieae (Scrophulariaceae)

University Of Alaska Fairbanks Campus, Fairbanks AK

Investigators

Abstract

This study addresses fundamental questions about the evolution of plant mating systems: (1) Why does self-pollination evolve? (2) Is selfing an evolutionary dead-end? (3) Can selfing vs. outbreeding strategies be reliably identified by particular floral features, such as timing of self-pollination? (4) Does evolution of particular mating systems lead to predictable changes in floral characteristics? The investigators will focus on an ideal system for investigating the above questions--the tribe Collinsieae, a diverse group of native, annual herbs that show evidence of repeated evolutionary shifts between selfing and outbreeding strategies. The research will involve field and laboratory studies to resolve precisely the mating systems of populations throughout the tribe, using genetic, developmental, and ecological data, and to reconstruct the dynamic history of mating-system change in the group. Evolution of selfing is of special interest to biologists and geneticists, who have long recognized that it can rapidly cause the loss of genetic variation, expression of deleterious traits, and loss of evolutionary potential. Different (conflicting) hypotheses proposed to explain evolution of selfing strategies have not been adequately tested and the basic question of whether selfing lineages can spawn outbreeding lines with long-term evolutionary prospects remains unanswered. Resolving these issues would greatly advance evolutionary biology and is a primary goal of this investigation.