VPW: Effect of Intraspecific Variation in Plant Quality on the Population Structure of Herbivores (Population Biology)

人口对环境变化的适应可以发生在极细微的尺度上。生长在重金属土壤上的植物可以在基因上与生长在正常土壤上的邻近植物区分开来，只有几米远。这种遗传隔离是土壤中金属的强大选择压力，以及跨越地雷边界的植物种群之间基因流动减少的选择的结果。在这项提案中，提出了一个问题，即引起植物种群分化的相同过程是否也能导致使用这些植物的食草动物种群的分化。将审查食草动物的迁移性、摄食专业化和接触金属对当地适应的存在或不存在的重要性。将选择8种不同的昆虫(4种专业取食者和4种多面性取食者--具有不同的传播能力)，这些昆虫出现在矿山尾矿上和矿山外的植物上。将收集每种物种的雌性昆虫后代的卵子，无论是从采矿地点还是正常地点。这些雌鸟的卵将被分成两批：一批将被放置在生长在重金属土壤上的植物上，另一批将被放置在附近生长在正常土壤上的植物上。这种相互转移实验将确定在金属土壤上收集的昆虫的后代是否比从受金属污染的植物的正常土壤上收集的昆虫的后代表现更好。如果是这样的话，那么已经发生了局部适应。如果能够利用含金属植物的食草动物与附近植物种群的食草动物在基因上存在差异，那么食草动物种群可能总体上以局部适应的个体斑块的形式存在，这些个体对植物质量的小范围变化做出反应。该项目进一步推动了VPW项目的目标，为女性提供通过研究提升她们在科学或工程领域的职业生涯的机会，并通过调查人员作为东道主校园榜样的更高知名度，鼓励其他女性在这些领域追求职业生涯。在这个项目中，促进第二个目标的拟议活动包括：教授两门课程--进化生态学和妇女在科学中的历史和作用研讨会；在系昆虫和植物科学系列研讨会上讲授个人研究；与昆虫学系的植物化学家和进化生态学家合作。

The adaptation of populations to environmental change can occur at extremely fine scales. Plants growing on heavy-metal soils can be genetically differentiated from neighboring plants growing only meters away on normal soils. Such genetic isolation is the result of strong selective pressures by metals in the soil coupled with selection for reduced gene flow between plant populations that span mine boundaries. In this proposal, it is asked whether the same processes that have given rise to population differentiation in plants can also cause differentiation in herbivore populations that use these plants. The importance of herbivore mobility, feeding specialization and exposure to metals to the presence or absence of local adaptation will be examined. Eight different insect species (4 specialist feeders and 4 generalists feeders - with difference dispersal abilities) that occur on plants both on and off mine tailings will be selected. Egg progeny of female insects, from both mined and normal sites, will be collected for each species. Eggs from these females will be split into two batches: one batch will be placed on plants growing on heavy-metal soil while the other will be placed on nearby plants growing on normal soils. Such reciprocal transfer experiments will allow determination if progeny from insects collected on metal soils fare better than progeny of insects collected from normal soils on metal-contaminated plants. If this is the case, then local adaptation has occurred. If herbivores capable of using metal-containing plants are genetically-differentiated from those on nearby plant populations, then it is possible that herbivore populations in general may exist as patches of locally-adapted individuals that are responding to small scale changes in plant quality. This project furthers VPW program objectives to provide opportunities for women to advance their careers in science or engineering through research, and to encourage other women to pursue careers in these areas through the investigators' enhanced visibility as role models on the host campuses. In this project, the proposed activities which contribute to the second objective include: teaching two courses, Evolutionary Ecology, and a seminar in the History and Role of Women in Science; giving lectures on personal research in the departmental Entomology and Plant Science seminar series; collaborating with a phytochemist and evolutionary ecologist in the Entomology department.