| Description |
All organisms must adapt to their environment to prosper. The measure of this in all organisms is fitness, the capacity to transmit their genetic information to the next generation. In some cases, the fitness of two organisms can be at odds with one another. This may happen both between two species and within a single species. When this occurs, the conflict that ensues drives some of the most rapid changes in all of evolution. These changes leave signals in the genome that are the consequence of their tumultuous past and point directly to the specific innovations that were chosen through the course of evolution to improve the fitness of a population. By studying these evolutionary conflicts, the specific details of these changes not only illuminate the course of evolutionary history but also further the understanding of the mechanisms of the genes under selection. Here, I will cover my work on evolutionary conflicts in two main areas. The first focuses on the conflict of the genomes of two closely related species, and their inability to hybridize. I investigate the genetics and molecular biology of this hybrid incompatibility to understand how two perfectly fit parents can fail to produce hybrid offspring. The second is centered on detecting a hallmark of evolutionary conflicts, recurrent positive selection, at the genomic scale. In these chapters I show how sperm channels from distant taxa have experienced similar selective pressures, indicating that similar evolutionary strategies are common over a wide range of conditions. I also conduct a genome-wide scan for recurrent positive selection in six clades of mammals, and present results that show that recurrent positive selection can target the same molecular interface over long stretches of evolutionary history. Together, this work provides two comprehensive examples of the impact that evolutionary conflict has on shaping the living world. |
