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

对于一个普通的观察者来说，很明显，同一物种的各个生物体在许多特征上往往是不同的。半个世纪前，当量化遗传变异的方法出现时，研究人员也发现了个体之间显著程度的遗传差异。虽然已经提出了许多理论来解释为什么会有如此多的遗传变异，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。该项目测试了一种假设，即当个体分布在精细空间尺度上变化的环境中时，种群内的大量遗传变异保持不变，不同的等位基因(基因的替代形式)在不同的环境条件下更受青睐。具体地说，全基因组测序将被用来在实验室实验中检验允许单一植物物种(固定环境)与多植物物种(可变环境)生活和觅食的植食性昆虫的遗传变异水平有何不同。此外，还将对自然种群的昆虫进行基因组测序，以推断以多种植物为食的昆虫是否保持了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保持昆虫种群内的遗传变异，而且还确定哪些基因允许昆虫适应由不同植物组成的食物。自然昆虫种群的遗传变异使其能够快速适应新的食物或环境。这些快速适应可以使昆虫对杀虫剂产生抗药性，并以抗虫作物品种为食，这可能会对农业和公共卫生产生重大影响，因为昆虫是主要的作物害虫和人类疾病的媒介。这个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很重要。此外，从该项目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领域代表性不足群体的本科生和高中生收集、解释和公开交流来自该项目的数据。

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.