Host mortality, predation and the evolution of parasite virulence
Host mortality, predation and the evolution of parasite virulence
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DOI：
10.1046/j.1461-0248.2003.00425.x
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发表时间：
2003-04-01
期刊：
影响因子：
8.8
通讯作者：
Day, T
中科院分区：
文献类型：
--
作者：
Choo, K;Williams, PD;Day, T
在关于毒力进化的理论文献中，最被接受的观点之一是，当寄主的背景死亡率增加时，寄生虫的毒力将进化到更高的水平。然而，令人惊讶的是，尽管许多背景死亡的来源都与捕食有关，但还没有任何理论研究明确地考虑这种重要的生态相互作用的动态如何影响毒力进化。在这里，我们考虑捕食如何通过显式地将捕食者引入经典的易感-感染-易感流行病学模型来影响毒力进化。我们发现，与先前的预测相反，不同的寄主死亡来源以不同的方式影响毒力进化。此外，毒力进化受到影响的方式取决于捕食者的动态与宿主种群的耦合程度，这可能会导致某种违反直觉的结果。例如，间接生态效应可导致寄主死亡率升高，从而导致较低的寄生虫毒力进化，即使这种升高的死亡率是由与捕食无关的因素引起的。
One of the most accepted views in the theoretical literature on virulence evolution is that a parasite's virulence will evolve to higher levels when its host's background mortality rate increases. Surprisingly, however, although many sources of background mortality involve predation, there has not yet been any theoretical research that explicitly considers how the dynamics of this important ecological interaction affects virulence evolution. Here, we consider how predation affects virulence evolution by explicitly introducing a predator into a classical susceptible-infected-susceptible epidemiological model. We find that, contrary to previous predictions, different sources of host mortality affect virulence evolution in different ways. Moreover, the way in which virulence evolution is affected depends on how tightly coupled the predator's dynamics are to the host population, and this can result in somewhat counterintuitive results. For example, indirect ecological effects can cause elevated host mortality to result in the evolution of lower parasite virulence, even if this elevated mortality arises from factors unrelated to predation.