Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
Proc Biol Sci. 2019 Sep 25;286(1911):20191811. doi: 10.1098/rspb.2019.1811.
There is evidence that human activities are reducing the population genetic diversity of species worldwide. Given the prediction that parasites better exploit genetically homogeneous host populations, many species could be vulnerable to disease outbreaks. While agricultural studies have shown the devastating effects of infectious disease in crop monocultures, the widespread nature of this diversity-disease relationship remains unclear in natural systems. Here, we provide broad support that high population genetic diversity can protect against infectious disease by conducting a meta-analysis of 23 studies, with a total of 67 effect sizes. We found that parasite functional group (micro- or macroparasite) affects the presence of the effect and study setting (field or laboratory-based environment) influences the magnitude. Our study also suggests that host genetic diversity is overall a robust defence against infection regardless of host reproduction, parasite host range, parasite diversity, virulence and the method by which parasite success was recorded. Combined, these results highlight the importance of monitoring declines of host population genetic diversity as shifts in parasite distributions could have devastating effects on at-risk populations in nature.
有证据表明，人类活动正在降低全球物种的种群遗传多样性。鉴于寄生虫更容易利用遗传上同质的宿主种群的预测，许多物种可能容易受到疾病爆发的影响。虽然农业研究表明传染病在作物单一种植中的破坏性影响，但在自然系统中，这种多样性-疾病关系的广泛性质仍不清楚。在这里，我们通过对 23 项研究进行荟萃分析，提供了广泛的支持，即高种群遗传多样性可以通过 67 个效应大小来预防传染病。我们发现寄生虫功能群（微观或宏观寄生虫）影响效应的存在，研究环境（野外或实验室环境）影响效应的大小。我们的研究还表明，无论宿主繁殖、寄生虫宿主范围、寄生虫多样性、毒力以及记录寄生虫成功的方法如何，宿主遗传多样性总体上都是抵御感染的有力防御。综合来看，这些结果强调了监测宿主种群遗传多样性下降的重要性，因为寄生虫分布的变化可能对自然界中处于危险中的种群产生毁灭性影响。
