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，这种寄生虫会降低健康和性能。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，寄生虫被预测将塑造宿主物种的生态和进化。这些预测适用于任何植物或动物宿主-寄生虫的相互作用，但测试它们需要一个物种，在该物种中，(1)寄生虫可以被操纵，(2)数千个个体的健康和表现可以在整个一生中进行测量。该项目使用一种定制的药物输送方法，从由数千只蜥蜴宿主组成的野生种群中清除几种不同种类的寄生虫。这些宿主寿命很短，发生在小岛上，那里的所有人口每年都可以进行几次准确的人口普查。最近开发出了每年将父母与后代配对的遗传方法，因此可以在驱虫和未经处理的治疗中测量数千个个体的终生存活和繁殖。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。这些结果将增加对传染病生态学和进化的理解，同时也考验基本的进化理论。该项目将通过暑期讲习班支持科学教师的专业发展，从而影响科学教育。这些讲习班的重点是培养数据收集、分析和绘图方面的技能，并将这些技能传授给K-12学生。在这个项目中，博士后、研究生和本科生研究人员将得到指导，重点是路易斯·斯托克斯少数民族参与联盟的本科生。尽管众所周知寄生虫会降低宿主的平均适合度，但很少有研究测试寄生虫是否影响宿主适应度的变异或探索由此导致的宿主种群的进化动力学。考虑到一生的整体健康状况，这一点尤其正确，众所周知，在大多数野生种群中很难衡量这一点。该项目将结合生态分子遗传学中的高通量新技术(GT-SEQ)和数量遗传学(动物模型)中已有的方法，在具有寄生虫负担的实验和自然变化的野生种群中提供关于总寿命适应性及其数量遗传结构的详细的、多代特征。数据集的性质还将允许将整个一生的适合度分解为其组成部分(幼虫存活、成虫存活、交配成功、繁殖成功)，并将疾病和寄生虫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的性别差异的关键进化假说提供更多的洞察力。暑期教师研讨会将与教育技术制造商合作完成，该技术向初中生传授数据技能，使用真实的统计数据和以精心策划的真实数据集为特色的“准备教学”模块。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.