DISSERTATION RESEARCH: Revealing the genomic targets of opposing natural selection that differ between females and males

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

Males and females of the same species share a genome and express many of the same traits. However, the two sexes often experience dramatic differences in natural selection on these shared traits. This can create an evolutionary tug-of-war when a trait and its underlying genes are beneficial in one sex, but detrimental in the other. This study will investigate this selection conflict in brown anole lizards. Such conflict can occur in any species with separate sexes and is predicted to have important implications for the evolution of differences between males and females, systems of sex determination, and the maintenance of genetic variation. The researchers will genetically sequence individuals from a wild population with extreme sex differences to identify genomic regions that are subject to this selection conflict. In addition, this project will provide research training for undergraduate students and the research will be used as the basis for developing field-tested educational materials designed to build skills for data interpretation in the K-12 classroom. Despite its implications for so many major questions in biology, sexual conflict has rarely been demonstrated in wild populations, and we have yet to identify the actual regions of the genome that are subject to sexual conflict in natural populations. This project has three aims: (1) test for sex differences in natural selection on a variety of traits, (2) test for fitness costs of sexual conflict by measuring the extent to which the genetic basis of fitness is correlated between males and females, and (3) combine field estimates of fitness with large-scale genomic data and powerful statistical methods to uncover genomic regions associated with sexual conflict in a wild population of brown anole lizards (Anolis sagrei). This work is being conducted using an island population of more than a thousand adult lizards that is highly amenable to large-scale studies of natural selection. The researchers will use their data to test whether the same genomic regions contribute to fitness in each sex, to measure the extent to which these genes are subject to sex differences in selection, and to determine which components of fitness (survival, reproductive success) give rise to intralocus sexual conflict.