论文标题
在不断变化的环境中的种群动态：随机切换与周期性切换
Population Dynamics in a Changing Environment: Random versus Periodic Switching
论文作者
论文摘要
环境变化极大地影响了人口的演变。在这里，我们研究了两种菌株人群的动态，一种人群的生长速度比另一个菌株稍快，在随机变化的二进制环境中竞争资源，该环境是通过随机或周期性切换在丰度和稀缺状态之间进行的。人口动态的特征是人口噪声（出生和死亡事件）与不同的环境结合在一起。我们阐明了经随机和周期性变化的环境的进化的相似性和差异。重要的是，通常发现在中间和快速随机切换下，人口大小的分布比周期性变化更广泛，这导致随机切换和周期性切换的固定概率之间的渐近行为明显不同。我们还确定了缓慢应变的固定概率最大的详细条件。
Environmental changes greatly influence the evolution of populations. Here, we study the dynamics of a population of two strains, one growing slightly faster than the other, competing for resources in a time-varying binary environment modeled by a carrying capacity switching either randomly or periodically between states of abundance and scarcity. The population dynamics is characterized by demographic noise (birth and death events) coupled to a varying environment. We elucidate the similarities and differences of the evolution subject to a stochastically- and periodically-varying environment. Importantly, the population size distribution is generally found to be broader under intermediate and fast random switching than under periodic variations, which results in markedly different asymptotic behaviors between the fixation probability of random and periodic switching. We also determine the detailed conditions under which the fixation probability of the slow strain is maximal.
