Abstract The effects of a single trait on more than one ecological function is called ecological pleiotropy. Traits that exhibit ecological pleiotropy are relevant to eco-evolutionary dynamics because the structure of interaction between the trait and its ecological functions alters how eco-evolutionary feedback loops emerge. Density-dependent selection (DDS) assumes that a single trait affects both density-independent and density-dependent population growth through ecological pleiotropy, and is one of the simplest routes for feedback loops. The r/K theory proposes a mechanism by which DDS occurs, but its predictions were poorly explored in an eco-evolutionary context. Some assumptions of the r/K theory seems to be relevant for the eco-evolution of predator-prey interactions. However, the relationship between these theories were poorly explored. Here, we investigate how does the r/K theory relates to the eco-evolution of predator-prey systems. We seek to answer two questions: (1) What are the system’s parameters that affect the predominance of r- and K-selection? (2) Does system’s qualitative behaviour depends on whether the predominant selection on prey population is an r- or a K-selection? To answer these questions, we built a model of differential equations describing the eco-evolutionary dynamics of a predator-prey system. We assume that prey vulnerability to predation is an adaptive trait that affects preys density-dependent growth rate through ecological pleiotropy. Then, we partitioned the selection gradient in its r- and K-selection components and evaluate how their magnitude relates to systems behaviour. We found that stable predator-prey cycles only occurs when K-selection is predominant. When r-selection is predominant, cycles lead to a runaway dynamics. Furthermore, the way predators parameters affect prey position in the r/K continuum depends on how they affect predation risk. While increasing predation risk increases K-selection, decreasing it increases r-selection. We discuss the relevance of the structure of ecological pleiotropy to our results and the perspectives that unifies the r/K theory and eco-evolutionary dynamics.

中文翻译：

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跨越 r/K 连续体的捕食者-猎物系统的生态进化动力学

摘要 单一性状对一种以上生态功能的影响称为生态多效性。表现出生态多效性的性状与生态进化动力学相关，因为性状与其生态功能之间的相互作用结构改变了生态进化反馈回路的出现方式。密度依赖选择 (DDS) 假设单个性状通过生态多效性影响密度独立和密度依赖的种群增长，并且是最简单的反馈回路途径之一。r/K 理论提出了 DDS 发生的机制，但在生态进化背景下对其预测的探索很少。r/K 理论的一些假设似乎与捕食者-猎物相互作用的生态进化有关。然而，这些理论之间的关系却没有得到很好的探讨。在这里，我们研究了 r/K 理论如何与捕食者-猎物系统的生态进化相关。我们试图回答两个问题：（1）影响 r 和 K 选择优势的系统参数是什么？(2) 系统的定性行为是否取决于对猎物种群的优势选择是 r 选择还是 K 选择？为了回答这些问题，我们建立了一个描述捕食者-猎物系统生态进化动力学的微分方程模型。我们假设猎物对捕食的脆弱性是一种适应性特征，它通过生态多效性影响猎物密度依赖的增长率。然后，我们在其 r 和 K 选择分量中划分选择梯度，并评估它们的大小与系统行为的关系。我们发现稳定的捕食者-猎物循环仅在 K 选择占主导地位时发生。当 r 选择占主导地位时，循环会导致动态失控。此外，捕食者参数影响 r/K 连续体中猎物位置的方式取决于它们如何影响捕食风险。虽然增加捕食风险会增加 K 选择，但降低它会增加 r 选择。我们讨论了生态多效性结构与我们的结果的相关性，以及统一 r/K 理论和生态进化动力学的观点。