The Genetic and Geographical Mosaics of Specialization: A Linkage Map-Based Analysis

物种形成的过程需要性状的进化，这些性状是基因流动的障碍。 这些障碍本身已经得到了很好的研究，但它们如何进化和持续存在的遗传细节仍然令人惊讶地模糊。 遗传连锁图谱的最新结果表明，专门针对不同作物植物的豌豆蚜虫小种在相对较少的关键基因组区域存在差异，这些早期物种之间的大部分基因组仍然非常相似。 该项目关注的是，与豌豆蚜虫的一个地理种群（纽约）中控制不同宿主植物使用的基因组区域相关联的相同遗传标记是否也与其他地点（爱荷华州和马里兰州）的豌豆蚜虫特化种族之间的分歧有关。 这将通过对每个地点的200只蚜虫进行基因分型来完成。 发现相同的标记标记不同的基因组区域在不同的专业人口将提高我们的理解的遗传过程中所涉及的进化不同的人口，并证明这些映射标记的实用程序在进一步分析豌豆蚜虫的专业化和物种形成的演变。 该项目将形成一种新的方法来研究生态专业化和物种形成的遗传机制的基础。 它还将作为本科生和研究生的多学科物种形成方法的培训基地。 此外，对作物害虫遗传学的研究将为农业昆虫学的未来工作提供信息并产生影响。 两个PI都积极参与旨在进一步了解农学家，保护生物学家，宗教领袖和公众之间的基本进化原理的外联活动。

The process of speciation requires the evolution of characters that act as barriers to gene flow. The barriers themselves are well studied but the genetic details of how they evolve and persist remain surprisingly obscure. Recent results from genetic linkage mapping reveal that races of pea aphids specialized on different crop plants differ at relatively few key genomic regions, with much of the genome remaining quite similar between these incipient species. This project concerns whether the same genetic markers linked to genomic regions controlling divergent host plant use in one geographical population of pea aphid (New York) are also associated with divergence between specialized pea aphid races in other locations (Iowa and Maryland). This will be accomplished by genotyping 200 aphids from each location. Finding that the same markers tag divergent genomic regions in different specialist populations will improve our understanding of the genetic processes involved in the evolution of divergent populations and demonstrate the utility of these mapped markers in further analyses of the evolution of specialization and speciation in pea aphids. This project will form the basis of a novel approach to the study of the genetic mechanisms of ecological specialization and speciation. It will also serve as a training ground in multidisciplinary approaches to speciation for undergraduates and graduate students. Moreover, this investigation of the genetics of crop pests will inform and influence future work in agricultural entomology. Both PIs are actively involved in outreach activities designed to further understanding of basic evolutionary principles among agriculturalists, conservation biologists, religious leaders and the general public.