Analysis of parasite host-switching: limitations on the use of phylogenies
Analysis of parasite host-switching: limitations on the use of phylogenies
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DOI：
10.1017/s0031182000084675
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发表时间：
1999-01-01
期刊：
影响因子：
2.4
通讯作者：
Jackson, JA
中科院分区：
文献类型：
--
作者：
Jackson, JA
即使是最普遍的寄生虫通常也只出现在潜在宿主物种的一个子集中，这种趋势反映了对其在自然界中的分布的压倒性的环境限制。以宿主转换为代表的这些限制的周期性变化可能是许多宿主-寄生虫组合进化中的一个重要过程。然而，要研究此类事件，必须首先确定它们发生的地点和时间。一组寄生虫内过去的宿主转换通常是通过寄生虫系统发育与宿主系统发育的比较来推断的。系统发育之间的一致性通常归因于遗传与共种的关联历史，以及“重复”寄生虫谱系中宿主转换或灭绝的不一致（在宿主树没有相应分支的情况下发生分歧）。讨论了从不一致模式中进行主机切换的推论。困难的出现是因为不一致常常可以通过生物学上不同的事件的不同组合来解释，而这些事件的相对概率是不确定的。此外，历史重建中隐含的宿主-寄生虫关系模型通常可能不允许除宿主转换或复制/灭绝之外的其他合理的不一致来源，或者在某些情况下，殖民化可能被“错误”一致性所掩盖。
Even the most generalist parasites usually occur in only a subset of potential host species, a tendency which reflects overriding environmental constraints on their distributions in nature. The periodic shifting of these limitations represented by host-switches may have been an important process in the evolution of many host-parasite assemblages. To study such events, however, it must first be established where and when they have occurred. Past host-switches within a group of parasites are usually inferred from a comparison of the parasite phylogeny with that of the hosts. Congruence between the phylogenies is often attributed to a history of association by descent with cospeciation, and incongruence to host-switching or extinction in 'duplicated' parasite lineages (which diverged without a corresponding branching of the host tree). The inference of host-switching from incongruent patterns is discussed. Difficulties arise because incongruence can frequently be explained by different combinations of biologically distinct events whose relative probabilities are uncertain. Also, the models of host-parasite relationships implicit in historical reconstructions may often not allow for plausible sources of incongruence other than host-switching or duplication/extinction, or for the possibility that colonization could, in some circumstances, be disguised by 'false' congruence.