Developing, unifying, and empirically testing theory for inducible and evolving defenses

在世界各地，猎物物种都有各种防御措施，以避免被捕食者吃掉。塑料防御是一种可以根据捕食者的数量随时间变化的防御系统，例如，当周围有更多的捕食者时，猎物可能会花更多的时间躲藏起来。进化的防御系统(如外壳厚度)随着时间的推移而变化，这是基于父母存活下来繁殖并能够将他们的特征传递给他们的后代。这些不同类型的防御会影响猎物及其捕食者的丰度，以及对环境变化的反应。然而，尚不清楚塑料和进化防御到底有什么影响，也不清楚塑料和进化防御对物种丰度及其对环境变化的反应是否有类似或不同的影响。发展这样一种理解很重要，因为人类正在通过营养丰富和物种死亡来显著改变环境。目前，还不可能预测不同类型的防御(塑料或进化)如何决定人口将如何反应。该项目使用实验室实验和数学模型来确定不同类型的塑料和不断演变的防御系统如何影响种群数量，以及种群如何对环境变化做出反应。这项研究计划将培养社区生态学和数学生物学领域的本科生和研究生，让未被充分代表的少数群体参与研究，并通过社区外联活动吸引公众参与。捕食者对捕食压力的适应性反应可以是可塑性的，也可以是进化的，两者都可以改变生态群落的动态和稳定性。这个项目的目标是开发理论，解释不同类型的塑料防御和不断演变的防御之间的机械差异如何塑造社区的动态。为了确定塑料和进化防御何时具有相似和不同的影响，将开发数学模型来解释塑料和进化防御如何影响系统稳定性和种群对营养丰富和物种死亡的反应。这一理论将通过实验室实验得到验证，实验涉及一种有或没有塑料防御的猎物物种(草履虫)的种群--行为和身体宽度的变化--改变了它们被捕食者吞噬的速度。这项工作将扩展目前的塑料防御理论，并将其与进化防御理论相统一。该项目的理论-数据配对方法可能会在塑料防御理论和群落生态学方面产生重要进展。这项工作还将深入了解塑料和进化适应之间的联系。这一奖项反映了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。

Throughout the world, prey species have a variety of defenses to avoid being eaten by predators. Plastic defenses are those that can change over time based on how many predators are present, for example prey may spend more time hiding when there are more predators around. Evolving defenses (like shell thickness) change over time based on which parents survive to reproduce and are able to pass their traits to their offspring. These different types of defenses influence the abundances of prey and their predators, as well as responses to environmental change. However, it is unclear exactly what effects plastic and evolving defenses have and whether plastic and evolving defenses have similar or different effects on species abundances and their responses to environmental change. Developing such an understanding is important because humans are dramatically altering environments through nutrient enrichment and species mortality. At present, it is not possible to predict how different types of defense (plastic or evolving) determine how populations will respond. This project uses laboratory experiments and mathematical models to determine how different types of plastic and evolving defenses influence population abundances and how populations respond to environmental change. This research program will train undergraduate and graduate students in the fields of community ecology and mathematical biology, engage underrepresented minorities in research, and engage the public through community outreach activities. Adaptive responses in prey to predation pressure can be plastic or evolutionary in nature, and both can alter the dynamics and stability of ecological communities. The goal of this project is to develop theory that explains how mechanistic differences between different types of plastic defenses and evolving defenses shape the dynamics of communities. To identify when plastic and evolving defenses have similar versus different effects, mathematical models will be developed to explain how plastic and evolving defenses influence system stability and population responses to nutrient enrichment and species mortality. The theory will be tested via laboratory based experiments involving populations of a prey species (Paramecium) that do or do not have plastic defenses - changes in behavior and body width - that alter the rate at which they are consumed by predators. This work will both extend current theory for plastic defenses and unify it with the theory for evolving defenses. The theory-data pairing approach of this project is likely to generate important advances in the theory of plastic defenses and community ecology. This work will also yield insight into the connections between plastic and evolutionary adaptation.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.