论文标题
在随机波动环境中休眠和种子库的分支过程模型
A branching process model for dormancy and seed banks in randomly fluctuating environments
论文作者
论文摘要
本文的目的是为（微生物）种群的进化益处的概念和定量理解做出贡献，以在面对波动的环境条件时保持种子库（由休眠个体组成）。为此，我们比较了“ 1型”bienayMé-galton-watson分支过程的长期行为（描述了仅由“活跃”个体组成的人群）与一类“ 2型”分支过程的长期行为，描述了由“活跃”和“活跃的人组成的人群）的长期行为。所有过程都嵌入在“苛刻”和“健康”条件之间随机变化的环境中，从而影响人群的生殖行为。对于2型分支过程，我们考虑了活动状态和休眠状态之间的几种不同的切换方案。我们还施加了总体资源限制，其中包括活跃和休眠后代的潜在不同的“生产成本”，从而导致不同人群之间的“公平比较”概念，并由于维持休眠状态而进行了生殖权衡。我们的切换制度包括从活动状态转到休眠状态的情况，反之亦然，无论环境状态如何（“自发切换”），但也是环境（“响应式切换”）以及合并策略的情况。事实证明，在某些情况下，切换策略可能是超临界的，而其他情况以及完全没有种子库，即使在“公平比较” WRT下，也是严格的次要临界。可用资源。在这种情况下，我们看到了超临界策略的明显选择性优势，即使在（可能很小的）生殖权衡的存在下，它也会保留。 [...]
The goal of this article is to contribute towards the conceptual and quantitative understanding of the evolutionary benefits for (microbial) populations to maintain a seed bank (consisting of dormant individuals) when facing fluctuating environmental conditions. To this end, we compare the long term behaviour of `1-type' Bienaymé-Galton-Watson branching processes (describing populations consisting of `active' individuals only) with that of a class of `2-type' branching processes, describing populations consisting of `active' and `dormant' individuals. All processes are embedded in an environment changing randomly between `harsh' and `healthy' conditions, affecting the reproductive behaviour of the populations accordingly. For the 2-type branching processes, we consider several different switching regimes between active and dormant states. We also impose overall resource limitations which incorporate the potentially different `production costs' of active and dormant offspring, leading to the notion of `fair comparison' between different populations, and allow for a reproductive trade-off due to the maintenance of the dormancy trait. Our switching regimes include the case where switches from active to dormant states and vice versa happen randomly, irrespective of the state of the environment (`spontaneous switching'), but also the case where switches are triggered by the environment (`responsive switching'), as well as combined strategies. It turns out that there are rather natural scenarios under which either switching strategy can be super-critical, while the others, as well as complete absence of a seed bank, are strictly sub-critical, even under `fair comparison' wrt. available resources. In such a case, we see a clear selective advantage of the super-critical strategy, which is retained even under the presence of a (potentially small) reproductive trade-off. [...]
