DISSERTATION RESEARCH: Does fine-scale habitat variation shape genomic diversity within populations?

对于一个不经意的观察者来说，很明显，同一物种的各个有机体在许多特征上往往彼此不同。当量化遗传变异的方法出现在半个世纪前时，研究人员也发现了个体之间显著的遗传差异。虽然已经提出了许多理论来解释为什么有这么多的遗传变异，但可能产生这种模式的不同过程的相对重要性仍然存在争议。该项目检验了一个假设，即当个体分布在一个精细的空间尺度上变化的环境中时，种群内的大量遗传变异得以维持，不同的等位基因（基因的替代形式）在不同的环境条件下受到青睐。具体而言，全基因组测序将用于研究在实验室实验中允许生活和喂养单一植物物种（不变环境）与多个植物物种（可变环境）的食草昆虫的遗传变异水平如何不同。此外，将对自然种群的昆虫进行基因组测序，以推断以多种植物物种为食是否能保持自然界昆虫种群的遗传多样性。该项目的目标不仅是确定环境变化在多大程度上可以维持昆虫种群内的遗传变异，而且还确定哪些基因可以使昆虫适应由不同植物组成的饮食。自然昆虫种群中的遗传变异可以快速适应新的饮食或环境。这些快速的适应性可以使昆虫获得对杀虫剂的抗性，并以抗虫害的作物品种为食，对农业和公共卫生产生巨大的影响，因为昆虫是主要的作物害虫和人类疾病的媒介。该项目的目标是了解昆虫的遗传变异是如何产生和维持的，这对于预测昆虫何时以及如何快速适应非常重要。此外，从该项目中获得的知识将对理解自然生态系统中物种相互作用的结果具有广泛的相关性，因为昆虫占地球上所有陆地动物物种的一半。最后，研究人员将指导来自科学代表性不足群体的本科生和高中生收集，解释和公开交流该项目的数据。

To a casual observer, it is obvious that individual organisms of the same species often differ from each other in many traits. When methods to quantify genetic variation emerged half a century ago, researchers discovered a remarkable degree of genetic differences among individuals as well. While many theories have been proposed to explain why there is so much genetic variation, the relative importance of different processes that could generate this pattern still remain controversial. This project tests the hypothesis that a large amount of genetic variation within populations is maintained when individuals are spread across environments that vary at a fine spatial scale, with different alleles (alternate forms of a gene) favored in different environmental conditions. Specifically, whole genome sequencing will be used to examine how levels of genetic variation differ in plant-feeding insects allowed to live and feed on a single species of plant (non-variable environment) versus multiple plant species (variable environment) in laboratory experiments. Additionally, genome sequencing of insects from natural populations will be conducted to infer if feeding on multiple plant species maintains genetic diversity within insect populations in nature. The goal of the project is to determine not only the extent to which environmental variation can maintain genetic variation within insect populations, but also which genes allow insects to adapt to diets consisting of different plants.Genetic variation in natural insect populations enables rapid adaptation to novel diets or environments. These rapid adaptations, which can allow insects to acquire resistance to insecticides and feed on pest-resistant crop breeds, can have dramatic consequences for agriculture and public health, since insects are major crop pests and vectors of human disease. The goal of this project, understanding how genetic variation in insects is generated and maintained, is important for predicting when and how rapid adaptation occurs in insects. In addition, knowledge gained from this project will have broad relevance for understanding the outcomes of species interactions in natural ecosystems, as insects comprise half of all terrestrial animal species on Earth. Lastly, researchers will mentor undergraduate and high school students from underrepresented groups in science in the collection, interpretation, and public communication of data from this project.