The evolution of parasite virulence and transmission rate in a spatially structured population
The evolution of parasite virulence and transmission rate in a spatially structured population
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DOI：
10.1006/jtbi.1999.1065
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发表时间：
2000-03-21
影响因子：
2
通讯作者：
Sasaki, A
中科院分区：
文献类型：
--
作者：
Haraguchi, Y;Sasaki, A
如果传播发生在一个空间结构的人口中的个人的局部接触，进化稳定（ESS）性状的寄生虫可能是完全混合的经典理论预测的很大不同。本文从理论上研究了寄生虫在格子结构宿主种群中的ESS毒力和传播率，其中宿主只能将后代发送到邻近的空位，并且传播仅发生在最近的感染者和易感者之间。邻居地点。被感染的宿主被认为是不育的。基于对近似和Monte Carlo模拟的分析表明，格型结构种群的ESS传播率和毒力都比完全混合种群的ESS传播率和毒力大幅度降低。与完全混合的种群不同，寄生虫的传播可以使宿主灭绝，因为即使宿主的整体密度变得非常低，靠近感染者的易感者的局部密度也可以保持很高。这种人口粘度和群体之间的选择自组织的空间集群的主机个人，然后导致一个中间ESS的传输率，即使没有之间的权衡传输率和毒力。当寄主繁殖率较大时，ESS传播率在一定范围内低于寄生虫灭绝区;当寄主繁殖率较小时，ESS传播率的演化导致寄生虫的淡出，而当寄主繁殖率较大时，ESS传播率的演化导致寄主的灭绝。(C)北京大学出版社.
If the transmission occurs through local contact of the individuals in a spatially structured population, the evolutionarily stable (ESS) traits of parasite might be quite different from what the classical theory with complete mixing predicts. In this paper, we theoretically study the ESS virulence and transmission rate of a parasite in a lattice-structured host population, in which the host can send progeny only to its neighboring vacant site, and the transmission occurs only in between the infected and the susceptible in the nearest-neighbor sites. Infected host is assumed to be infertile. The analysis based on the pair approximation and the Monte Carlo simulation reveal that the ESS transmission rate and virulence in a lattice-structured population are greatly reduced from those in completely mixing population. Unlike completely mixing populations, the spread of parasite can drive the host to extinction, because the local density of the susceptible next to the infected can remain high even when the global density of host becomes very low. This demographic viscosity and group selection between self-organized spatial clusters of host individuals then leads to an intermediate ESS transmission rate even if there is no tradeoff between transmission rate and virulence. The ESS transmission rate is below the region of parasite-driven extinction by a finite amount for moderately large reproductive rate of host; whereas, the evolution of transmission rate leads to the fade out of parasite for small reproductive rate, and the extinction of host for very large reproductive rate. (C) 2000 Academic Press.