DISSERTATION RESEARCH: Male fitness in a single cell: The evolutionary significance of male reproductive cell morphology

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

The goals of this project are to understand how natural selection acts on male reproductive cell characteristics both within and among species. A central aim of evolutionary biology is describing the sources of diversity in traits within and among species. Traits that confer an advantage in securing a mate are often highly diverse. Though historically research has focused on extravagant traits, such as plumage or horn size, relatively little research has focused on such traits directly involved in fertilization. The male reproductive cell is the most diverse cell type among animals, ranging from a few micrometers in some species to 6 cm in length in others, and is central to male reproductive success. Because males of all animal species produce such cells, studying them provides a unique model for exploring how selection shapes the evolution a trait critical for fertilization across the animal kingdom. The project goals will be achieved through a combination of field work, microscopy, and new genomic methods for identifying paternity in a population of nearly two thousand lizards. My proposed studies will test the hypothesis that the strength and direction of selection on traits within a species will be mirrored in patterns of evolution among species. This project is broken into three aims: 1) testing for correlated evolutionary changes between male reproductive cell morphology and proxies for both pre and post-copulatory selection, 2) measuring phenotypic plasticity and fitness consequences of morphology within a species and 3) measuring selection on morphology, quantity and quality in a wild population. The proposed improvement (aim 3), will allow for the measurement of selection on these traits in a wild population of brown anole lizards using recently developed genomic methods for constructing pedigrees. Together, these projects will integrate microevolutionary processes with macroevolutionary patterns to better understand the evolution of the male gamete.