Evolutionary Genetics and the Ecology of Speciation

为什么会有这么多的动物物种？为什么这么多物种在生态上是专门化的，使用的资源和栖息地范围很窄？ 生物学家长期以来一直怀疑生态专业化和物种形成（=物种形成）之间存在因果关系。然而，“生态物种形成”模型的实证测试是极其罕见的。 该项目评估了与北美东部不同树种（宿主植物）相关的Neochlamisus bebbium-leaf甲虫的种群。 具体来说，它实验量化的能力与不同树种的甲虫种群利用对方的宿主植物和他们的意愿，以彼此交配，并通过收集DNA序列和蛋白质多态性数据，这些人群之间的遗传交换模式进行评估。 这些数据在个体和群体水平上进行整合和分析，以测试各种关于不同遗传和环境机制的假设，生态分歧可能会推动物种形成和生物多样性。 这种对物种形成生态学的研究是罕见的，但对于理解地球巨大生物多样性的起源至关重要。 由于许多植食性昆虫（包括一些Neochlamisus物种）也是经济害虫，因此了解决定昆虫使用哪些植物的因素，如何使用植物，以及新的植食性昆虫种群和物种的形成具有应用和学术重要性。 昆虫-植物关系的生态学原理正越来越多地用于制定农业战略。 目前的建议将提供深入了解这些原则以及它们对物种形成的影响。

Why are there so many animal species? Why are so many species ecologically specialized, using a narrow range of resources and habitats? Biologists have long suspected that ecological specialization and species formation (= speciation) are causally connected. However, empirical tests of "ecological speciation" models are extremely rare. This project evaluates populations of Neochlamisus bebbianae leaf beetles that are associated with different tree species (host plants) in eastern North America. Specifically, it experimentally quantifies the ability of beetle populations associated with different tree species to use each other's host plants and their willingness to mate with each other, and it evaluates patterns of genetic exchange among these populations by collecting DNA sequences and protein polymorphism data. These data are integrated and analyzed at the individual and population levels to test a variety of hypotheses on the diverse genetic and environmental mechanisms by which ecological divergence may drive speciation and biological diversification. Such investigations on speciation ecology are rare yet critical for understanding the origins of Earth's tremendous biodiversity. Because many herbivorous insects (including some Neochlamisus species) are also economic pests, understanding the factors that determine which plants an insect uses, how plants are used, and how new herbivorous insect populations and species form is of applied as well as academic importance. Ecological principles underlying insect-plant relationships are increasingly being used to develop agricultural strategies. The current proposal will provide insights into these principles as well as their consequences for speciation.