Predation shifts coevolution toward higher host contact rate and parasite virulence
Predation shifts coevolution toward higher host contact rate and parasite virulence
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DOI：
10.1098/rspb.2021.2800
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发表时间：
2022-07-13
影响因子：
4.7
通讯作者：
Cressler, Clayton E. E.
中科院分区：
文献类型：
--
作者：
Walsman, Jason C. C.;Cressler, Clayton E. E.
昆虫可以通过减少社会接触来避免寄生虫（和病原体），但这种隔离可能会带来成本，例如增加对捕食者的脆弱性。因此，许多捕食者-宿主-寄生物系统面临着宿主在捕食和寄生之间的权衡。与此同时，寄生虫进化出更高的毒力，以应对宿主社会性的增加，从而增加多重感染。捕食如何改变宿主行为和寄生虫毒力的共同进化？如果捕食者是有选择性的，即捕食者不成比例地捕捉最生病的宿主呢？我们回答这些问题与参数化的特立尼达孔雀鱼Gyrodactylus物种的生态协同进化模型。系统在这里，增加捕食驱动主机协同进化的更高的分组，选择更高的毒性。此外，更高的捕食者选择性驱动接触率更高和毒性更低。最后，我们展示了捕食和选择性如何对宿主密度和流行率产生非常不同的影响，这取决于宿主或寄生虫是否进化，或两者兼而有之。例如，较高的捕食者选择性导致较低的流行率，没有进化或只有寄生虫进化，但较高的流行率与主机进化或共同进化。这些研究结果告知我们的理解不同的系统中，主机的行为反应捕食可能会导致寄生虫的流行和毒力增加。
Hosts can avoid parasites (and pathogens) by reducing social contact, but such isolation may carry costs, e.g. increased vulnerability to predators. Thus, many predator-host-parasite systems confront hosts with a trade-off between predation and parasitism. Parasites, meanwhile, evolve higher virulence in response to increased host sociality and consequently, increased multiple infections. How does predation shift coevolution of host behaviour and parasite virulence? What if predators are selective, i.e. predators disproportionately capture the sickest hosts? We answer these questions with an eco-coevolutionary model parametrized for a Trinidadian guppy-Gyrodactylus spp. system. Here, increased predation drives host coevolution of higher grouping, which selects for higher virulence. Additionally, higher predator selectivity drives the contact rate higher and virulence lower. Finally, we show how predation and selectivity can have very different impacts on host density and prevalence depending on whether hosts or parasites evolve, or both. For example, higher predator selectivity led to lower prevalence with no evolution or only parasite evolution but higher prevalence with host evolution or coevolution. These findings inform our understanding of diverse systems in which host behavioural responses to predation may lead to increased prevalence and virulence of parasites.