Eco-evolutionary dynamics of parasitism mediated through variance in host fitness

几乎所有的动物和植物都被寄生虫感染，这会降低健康和生产能力。除了这些总体影响外，预计寄生虫还会增加个体宿主在健康和性能方面的差异。因此，寄生虫被预测会影响宿主物种的生态和进化。这些预测适用于任何植物或动物的宿主-寄生虫相互作用，但要验证这些预测，需要一个物种，其中：(1)寄生虫可以被操纵，(2)可以在整个生命周期中测量数千个个体的健康和性能。该项目使用一种定制的药物输送方法，从由数千只个体蜥蜴宿主组成的野生种群中去除几种不同种类的寄生虫。这些寄主是短命的，发生在小岛上，每年可以准确地对整个人口进行几次普查。最近已经开发出每年将父母与后代进行匹配的遗传方法，因此可以在除虫和未经治疗的情况下测量数千个个体的终生生存和繁殖。该项目将测试寄生虫是否以及如何影响宿主健康和性能的变化。研究结果将增加对传染病生态学和进化的理解，同时也将检验基本的进化理论。该项目将通过夏季讲习班支持科学教师的专业发展，从而影响科学教育。讲习班的重点是培养数据收集、分析和绘图的技能，并将这些技能传授给K-12学生。博士后、研究生和本科生研究人员将在这个项目中得到指导，重点是路易斯·斯托克斯少数民族参与联盟的本科生。虽然众所周知，寄生虫降低了宿主的平均适合度，但很少有研究测试寄生虫是否影响宿主适合度的变化或探索宿主种群的进化动态。考虑到大多数野生种群的终生适应度是出了名的难以衡量的，这一点尤其正确。该项目将结合新的高通量生态分子遗传学技术（GT-seq）和已建立的定量遗传学方法（动物模型），在具有寄生虫负荷实验和自然变化的野生种群中，提供详细的、多代的总终生适应度及其定量遗传结构特征。该数据集的性质还允许将总生命适应度分解为其组成部分（幼年生存、成年生存、交配成功、繁殖成功），并将疾病和寄生的进化动力学分别考虑为雌性和雄性，从而为关于选择和寄生虫抗性和耐受性中的性别差异的关键进化假设提供额外的见解。暑期教师研讨会将与教育技术制造商合作进行，这些教育技术制造商利用真实的统计数据，结合以精心策划的真实数据集为特色的“随时可教”模块，向初高中学生教授数据技能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nearly all animals and plants are infected by parasites that can reduce health and performance. In addition to these overall effects, parasites are predicted to increase variation among individual hosts in health and performance. Parasites are therefore predicted to shape the ecology and evolution of the host species. These predictions apply to any plant or animal host-parasite interaction but testing them requires a species in which (1) parasites can be manipulated and (2) health and performance can be measured across the entire lifetime for thousands of individuals. This project uses a custom drug delivery method to remove several different species of parasitic worm from a wild population comprised of thousands of individual lizard hosts. These hosts are short-lived and occur on small islands where the entire population can be accurately censused several times per year. Genetic methods have recently been developed to match parents to offspring each year, so lifetime survival and reproduction can be measured for thousands of individuals, in both de-wormed and untreated treatments. The project will test whether and how parasites influence variation in host health and performance. The results will increase understanding of the ecology and evolution of infectious disease while also testing fundamental evolution theory. The project will impact science education by supporting the professional development of science teachers through summer workshops. The workshops focus on building skills in data collection, analysis, and graphing, and in transmitting those skills to K-12 students. Postdoctoral, graduate, and undergraduate researchers will be mentored in this project, with a focus on undergraduates in the Louis Stokes Alliance for Minority Participation.Although it is well known that parasites reduce the mean fitness of their hosts, few studies have tested whether parasites influence variance in host fitness or explored the resulting evolutionary dynamics for host populations. This is particularly true when considering total lifetime fitness, which is notoriously difficult to measure in most wild populations. This project will combine new high-throughput techniques in ecological molecular genetics (GT-seq) with established approaches in quantitative genetics (animal models) to provide a detailed, multi-generational characterization of total lifetime fitness and its quantitative genetic architecture in a wild population with both experimental and natural variation in parasite burdens. The nature of the dataset will also allow total lifetime fitness to be decomposed into its components (juvenile survival, adult survival, mating success, reproductive success), and for evolutionary dynamics of disease and parasitism to be considered separately for females and males, thus providing additional insight into key evolutionary hypotheses about sex differences in selection and in parasite resistance and tolerance. The Summer Teacher Workshop will be done in collaboration with makers of educational technology that teaches data skills to middle- and high-school students using authentic statistics combined with “ready- to-teach” modules featuring curated real datasets.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.