The evolutionary forces that drive patterns of genetic diversity within and between species 197 views

Natural genetic diversity describes the historical patterns of selection, demography, and drift that act upon populations. With the widespread proliferation of next generation sequencing (NGS) technologies and abundance of genomic tools, we can investigate the evolutionary mechanisms that leave distinct signals across the genome. By utilizing genome-wide diversity information and population-based datasets, we can begin to elucidate the ways in which organisms evolve and predict how they might respond to novel environmental changes. My dissertation studies the population genetics and natural selection pressures on several taxa within the Daphnia pulex species complex, a group of freshwater microcrustaceans that rapidly adapt to changing environments. I also studied the patterns of genetic diversity and demography influencing a metapopulation of Drosophila melanogaster (i.e., the common fruit fly) within Charlottesville, Virginia, USA. In my first chapter, I analyze general patterns of gene family evolution and selection across Daphnia genomes. My second chapter delves into the evolutionary mechanisms that maintain variation between cryptic species of D. pulex. My third chapter examines the demographic consequences of overwintering bottlenecks in Drosophila melanogaster. Ultimately, my dissertation contributes to the evolutionary mechanisms that influence genetic diversity within and between species. Through detailed genomic analyses, I laid the groundwork for understanding genomic change and aided the scientific community by contributing to the understanding of both the long- and short-acting evolutionary processes shaping patterns of variation.

PHD (Doctor of Philosophy)

Biology; Population genetics; Natural selection; Genetic diversity; Daphnia pulex; Drosophila melanogaster; Evolutionary genetics; Balancing selection

English

2024-07-08