Dissertation Research: The Evolution of Specialized Floral Phenotypes in a Generalist Pollination Environment: Fitness Trade-offs in a Dudleya Species Complex

University Of California-Riverside, Riverside CA

Investigators

Abstract

Plants that are pollinated by several different types of animal nevertheless often have features which appear to adapt them to one particular type. The proposed research explores how such specialized adaptations can arise in a generalized "pollination environment", using several related plant species native to the southwestern US. Experiments in natural populations and in a flight cage will determine which pollinators (hummingbirds or bumblebees) are most important in selecting for particular features of flowers (flower length and width), and the degree to which flowers better adapted to one pollinator still can make use of the other. By exploring how floral adaptation arises, the research furthers our understanding of the evolution of distinct plant species, and thus the generation of biodiversity. An accelerating "biodiversity crisis", caused by extinction of species from human activities, is central to the science of conservation biology. Conservation biologists must understand how to prevent extinctions, but equally must understand the conditions that allow new species to evolve to replace extinct ones. The proposed experiments with a model plant-pollinator system will help us understand how the great diversity of flowering plant species has evolved, and thus how to promote ongoing evolution of new species and maintenance of biodiversity.