Dissertation Research: Ecological Genetics of Life-history Evolution in Mimulus guttatus

Duke University, Durham NC

Investigators

Abstract

A central goal of biology is to understand ecological and genetic factors which have contributed to the diversity of life. Adaptation to different ecological conditions occurs through changes in the genome and in visible traits. Few studies have analyzed the genomic differences underlying divergence. This project aims to answer fundamental questions regarding the adaptive differences between two dramatically different wild populations of Mimulus guttatus (yellow monkeyflower). One population consists of tiny, small flowered annual plants living in extreme alpine conditions. The other population includes large-flowered perennials inhabiting sand dunes in a coastal temperate environment. This study will use genome mapping approaches to identify and characterize the genetic basis of trait differences in a common garden environment. In addition, this experiment will reveal how particular genotypes perform in different natural environments with respect to fitness. By analyzing recombinant inbred lines (advanced generation hybrids between annual and perennial) in a reciprocal transplant experiment, fitness variation associated with specific genomic regions in each of the two natural environments will be assessed. This genetic dissection of local adaptation will help clarify which traits and chromosome regions are associated with performance in the wild. Results of these experiments will provide an unusually complete understanding of basic evolutionary questions, such as how genetic differences contribute to an organisms' ability to occupy diverse ecological environments.