资源受限且存在大规模死亡事件的种群中快慢生活史策略的演化
Evolution of Fast and Slow Life Histories in Resource-Constrained Populations with Mass-Mortality Events
AI总结：
本研究通过数学模型证明，在资源受限且经历大规模死亡事件的种群中，人口随机性偏好慢生活史，而灾难事件创造资源丰裕期偏好快生活史，两者平衡产生演化吸引速度，为r/K选择提供严格数学框架。
AI中文摘要：
我们研究了在受单一生长限制资源约束、并经历人口统计随机性和大规模死亡事件的种群中，生活史速度的演化。我们聚焦于一个准中性机制，其中竞争类型具有相同的资源利用效率，但生活史速度不同。在大承载能力的尺度极限下，我们将模型简化为一维跳跃扩散过程，该过程支持在生态平衡流形上。漂移和扩散分量捕捉了人口统计随机性和密度调节的联合效应，而跳跃分量则由灾难性死亡事件驱动。利用这一极限过程，我们推导了入侵类型固定概率的一阶近似，该入侵类型的生活史速度与常驻种群略有不同。计算表明，小规模人口统计事件倾向于有利于较慢的生活史，而灾难性死亡事件则创造了资源丰富的短暂时期，有利于较快的类型。这两种演化力量的相互作用允许存在一个非平凡的演化吸引性生活史速度，该速度是灾难性死亡事件频率和强度的增函数。这些结果为一些经典的r/K选择论点提供了严格的数学框架，并进一步展示了大规模死亡事件如何在资源受限的种群中维持对更快生活史的选择。
英文摘要：
We study the evolution of the speed of life history in populations competing for a single growth-limiting resource subject to demographic stochasticity and mass mortality events. We focus on a quasi-neutral regime in which competing types have equal resource-use efficiency but differ in life-history speed. In the large-carrying-capacity scaling limit, we reduce the model to a one-dimensional jump-diffusion supported on the manifold of ecological equilibria. The drift and diffusion components capture the joint effects of demographic stochasticity and density regulation, while the jump component is driven by the catastrophic mortality events. Using this limiting process, we derive a first-order approximation for the fixation probability of an invading type that differs slightly in life history speed from the resident population. Calculations show that small demographic events tend to favor slower life histories, whereas catastrophic mortality events create transient periods of resource abundance that benefit faster types. The interaction of these two evolutionary forces allows for the existence of a nontrivial evolutionarily attractive life-history speed, which is an increasing function of the frequency and intensity of the catastrophic mortality events. These results provide a rigorous mathematical framework for some classical r/K-selection arguments, and furthermore demonstrate how mass mortality events can maintain selection for faster life histories even in resource-constrained populations.
