Dissertation Research: Overdominance and the Maintenance of Genetic Variation for Fitness

影响生存和繁殖成功的遗传变异似乎在动物种群中很常见，这是自相矛盾的，因为自然选择预计会从基因库中消除有害的遗传变异。了解维持如此广泛的适应性变化的过程是进化生物学研究的主要目标。拟议的研究将群体遗传学理论与果蝇（Drosophila melanogaster）X染色体适应性变化的实验相结合，以测试适应性变化的有影响力的模型-超显性选择-通过支持遗传变异的个体来保持遗传多样性。通过对X连锁变异的研究，可以将与超显性选择过程相关的模式从其他进化过程产生的潜在模糊模式中解脱出来。这项研究将揭示选择在保护群体遗传变异中的作用，并将对相关生物学学科，特别是旨在减轻近亲繁殖负面影响的学科（例如，畜牧业和野生动物保护），或了解人类遗传疾病的原因和持久性。该项目还提供了丰富的机会，教学和介绍本科生的原创性研究。

Genetic variation affecting survival and reproductive success appears to be common in animal populations and is paradoxical because natural selection is expected to eliminate harmful genetic variants from the gene pool. Understanding the processes maintaining such widespread fitness variation is a major goal of evolutionary biology research. The proposed research merges population genetics theory with experiments on X-chromosome fitness variation in the fruit fly (Drosophila melanogaster) to test an influential model of fitness variation - overdominant selection - that maintains genetic diversity by favoring individuals that are genetically variable. By focusing on X-linked variation, patterns associated with the overdominant selection process can be disentangled from potentially obscuring patterns produced by other evolutionary processes.This research will shed light on the role of selection in preserving population genetic variation, and will have important implications for related biological disciplines, particularly those aiming to mitigate the negative effects of inbreeding (e.g., animal husbandry and wildlife conservation), or understand the causes and persistence of human genetic disease. The project also provides a wealth of opportunities for teaching and introducing undergraduate students to original research.