US-Israel Collab: Are parasites in complex communities more evolvable? Bridging ecology and evolution with computational modeling and rodent-bacteria evolution experiments

人们越来越认识到，进化在传染病的出现和重新出现中发挥着核心作用。然而，我们对为什么一些病原体和寄生虫能迅速适应新环境而另一些不能的理解仍然不完整。一些寄生虫快速进化的能力（即，进化能力）允许它们“跳跃”感染新的宿主物种。这个项目将研究一些相互作用的动物和微生物的自然群落是否以及如何产生有利于进化性进化的条件。了解为什么会出现进化性变异，可以帮助识别潜在的新发疾病，并为降低其传播能力的管理策略提供信息。从直觉上讲，更大的进化能力对寄生虫有利，但进化能力并不直接增加寄生虫的繁殖或生存能力。因此，不太清楚它是如何在人群中产生或维持的。计算机模拟的结果表明，在不可预测和不断变化的环境中，进化是有利的。该项目利用计算机模拟宿主-寄生虫共同进化，并利用自然细菌-啮齿动物系统进行实地和实验室实验，以确定寄生虫生态学促进或阻碍进化能力进化的具体方面。该项目是与以色列科学家合作的。 它将为科学界开发新的计算工具，为本科和中学课堂开发材料，并为密歇根州的教师提供教师培训和研究经验。寄生虫种群通常在复杂的群落中进化，其中多个宿主物种具有重叠的范围，并且在单个宿主中发生多种感染。该项目将解决四个中心目标：1）量化宿主异质性对寄生虫进化性和多样性的影响; 2）测量宿主异质性如何影响多种寄生虫共感染的流行率和强度; 3）确定寄生虫共感染对进化性和多样性的影响;和4）量化宿主异质性和寄生虫共感染对进化性和多样性的综合影响。使用Avida进行的实验，Avida是一个计算平台，数字宿主和寄生虫以开放的方式进化，将以外地-在以色列内盖夫沙丘使用巴尔通体寄生虫及其野生啮齿类宿主进行现场采样和实验室进化实验。该奖项反映了NSF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进行评估，被认为值得支持的搜索.

There is a growing appreciation that evolution plays a central role in the emergence and reemergence of infectious diseases. However, our understanding of why some pathogens and parasites rapidly adapt to novel environments, while others don't, remains incomplete. This ability of some parasites to evolve rapidly (i.e., evolvability) allows them to "jump" into infecting new host species. This project will examine whether and how some natural communities of interacting animals and microbes generate conditions that favor the evolution of evolvability. Understanding why variation in evolvability arises can help to identify potential emerging diseases and inform management strategies that reduce their ability to spread. It makes intuitive sense that greater evolvability is beneficial for the parasite, but evolvability does not directly increase the parasite's reproduction or survivorship. Thus, it is less clear how it arises or is maintained in populations. Results from computer simulations suggest that evolvability is advantageous in unpredictable and constantly changing environments. The project uses computer simulations of host-parasite coevolution as well as field and laboratory experiments using a natural bacteria-rodent system to identify specific aspects of parasite ecology that promote or hinder the evolution of evolvability. This project is a collaboration with Israeli scientists. It will develop new computational tools for the scientific community, materials for undergraduate and secondary school classrooms, as well as teacher training and research experience for teachers in Michigan. Parasite populations typically evolve in complex communities, where multiple host species have overlapping ranges, and multiple infections occur within a single host. This project will address four central aims: 1) quantifying the effect of host heterogeneity on parasite evolvability and diversity; 2) measuring how host heterogeneity influences the prevalence and intensity of coinfection by multiple parasite species; 3) identifying the effect of parasite coinfection on evolvability and diversity; and 4) quantifying the combined effects of host heterogeneity and parasite coinfection on evolvability and diversity. Experiments using Avida, a computational platform where digital hosts and parasites evolve in an open-ended fashion, will be complemented by a combination of field-site sampling and laboratory evolution experiments using Bartonella parasites and their wild rodent hosts in the Israeli Negev Dunes.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.