SG: Parasitism as a selective pressure on seasonal migration

尽管帝王蝶和座头鲸看起来并不像，但它们有一个重要的共同点：它们每年都会进行跨越数千英里的季节性迁徙。他们并不孤单。短距离和长距离的迁徙是一种普遍的动物行为。为什么有这么多物种冒着迁徙的危险和不确定性的风险，这是一个谜。存在许多理论来帮助理解这种看似代价高昂的行为是如何演变的。要评估这些，有必要考虑细微之处，即寄生虫和病原体所起的作用。通过结合动物运动和传染病生态学的知识，研究人员将开发数学模型来研究迁徙的进化。这项研究不仅将加深我们对寄主运动和寄生虫的理解，而且将推动更广泛的迁徙理论的发展。充分了解是什么因素推动了移民，对于预测未来移民模式将如何继续适应性变化至关重要。该项目将解决广泛的社会和经济利益问题，如迁徙的野生动物和牲畜之间的疾病传播。这也将有助于我们理解越来越多的人类旅行对紧急疾病的影响。研究人员将通过明尼苏达大学的教学模块让本科生参与进来。此外，他们还将为独立研究项目提供机会。研究结果将在贝尔自然历史博物馆向公众公布。尽管人们对宿主迁移如何与病原体和寄生虫感染相互作用越来越感兴趣，但没有严格的框架来组织、解释和预测这些相互作用。宿主的移动可以增加或减少宿主对寄生虫的暴露，而言语模型产生了相互矛盾的预测。对每一种结果可能发生的时间缺乏了解，这严重阻碍了我们预测环境条件变化对迁徙和宿主-寄生虫动态的潜在后果的能力。这项研究是克服这一障碍的第一步。它将使用概念验证数学模型来严格测试特定假设和由此产生的关于宿主运动和寄生虫的预测之间的联系。这项工作的目标是开发广泛适用于整个系统但尚未被考虑的模型。分析模型将被用来测试(A)寄生虫传播模式(直接宿主对宿主接触，而不是间接通过环境)，(B)感染成本的类型(生存或繁殖力)，以及(C)寄生虫传播的空间/时间方面如何影响进化稳定策略。该项目将寻找促进迁徙行为进化的参数空间。结果将突出参数空间的某些区域值得进一步探索。这将建议更详细的模型在哪些领域特别有用，这些模型被参数化为特定的研究系统。研究结果还将提供一套理论假设，可以使用已有的数据集进行测试。

Although monarch butterflies and humpback whales do not look alike, they have one important thing in common: every year, they embark on a seasonal migration that spans thousands of miles. They are not alone. Migration over short and long distances is a widespread animal behavior. Just why so many species risk the perils and uncertainties of migration is a puzzle. Many theories exist to help understand how this seemingly costly behavior evolved. To evaluate these, it is necessary to think small, namely, at the role played by parasites and pathogens. By combining knowledge from animal movement and infectious disease ecology, the researchers will develop mathematical models to study the evolution of migration. This research will not only improve our understanding of host movement and parasites, but will also advance migration theory broadly. Fully understanding what factors drive migration is crucial for predicting how migratory patterns will continue to adaptively change in the future. This project will address a broad range of problems of social and economic interest such as disease spread between migrating wildlife and livestock. It also will help our understanding of the influence of increasing human travel on emergent diseases. The researchers will engage undergraduate students through teaching modules at the University of Minnesota. In addition, they will provide opportunities for independent research projects. The research findings will be communicated to the public at the Bell Museum of Natural History. Despite growing interest in how host migration interacts with infection by pathogens and parasites, there is no rigorous framework to organize, interpret, and predict these interactions. Host movement can either increase or decrease host exposure to parasites and verbal models have generated conflicting predictions. The lack of understanding of when each outcome is likely to occur represents a serious roadblock in our ability to anticipate potential consequences of shifting environmental conditions for both migration and host-parasite dynamics. This research is the first step in overcoming this obstacle. It will use proof-of-concept mathematical models to rigorously test the links between specific assumptions and resulting predictions regarding host movement and parasites. The goal of the work is to develop models that are broadly applicable across systems, but have not yet been considered. Analytical models will be used to test how (a) parasite transmission mode (direct host-to-host-contact versus indirectly through the environment), (b) type of infection cost (survival or fecundity), and (c) spatial/temporal aspects of parasite transmission influence Evolutionarily Stable Strategies. The project will search for the parameter space that promotes evolution of migratory behaviors. The results will highlight certain regions of parameter space as deserving further exploration. This will suggest areas in which more detailed models, parameterized to a specific study system, will be especially useful. The results will also provide a set of theoretical hypotheses that can be tested using already available datasets.