Su Min, Boots Mike
School of Mathematics, Hefei University of Technology, Hefei 230009, China; Integrative Biology, University of California, Berkeley, CA 94720, USA.
Integrative Biology, University of California, Berkeley, CA 94720, USA.
J Theor Biol. 2017 Mar 7;416:1-7. doi: 10.1016/j.jtbi.2016.12.017. Epub 2016 Dec 23.
Understanding the drivers of parasite evolution and in particular disease virulence remains a major focus of evolutionary theory. Here, we examine the role of resource quality and in particular spatial environmental heterogeneity in the distribution of these resources on the evolution of virulence. There may be direct effects of resources on host susceptibility and pathogenicity alongside effects on reproduction that indirectly impact host-parasite population dynamics. Therefore, we assume that high resource quality may lead to both increased host reproduction and/or increased disease resistance. In completely mixed populations there is no effect of resource quality on the outcome of disease evolution. However, when there are local interactions higher resource quality generally selects for higher virulence/transmission for both linear and saturating transmission-virulence trade-off assumptions. The exception is that in castrators (i.e., infected hosts have no reproduction), higher virulence is selected for both low and high resource qualities at mixed local and global infection. Heterogeneity in the distribution of environment resources only has an effect on the outcome in castrators where random distributions generally select for higher virulence. Overall, our results further underline the importance of considering spatial structure in order to understand evolutionary processes.
理解寄生虫进化的驱动因素，尤其是疾病毒力，仍然是进化理论的一个主要焦点。在此，我们研究资源质量的作用，特别是这些资源分布中的空间环境异质性对毒力进化的影响。资源可能对宿主易感性和致病性有直接影响，同时对繁殖有影响，进而间接影响宿主 - 寄生虫种群动态。因此，我们假设高资源质量可能导致宿主繁殖增加和/或抗病性增强。在完全混合的种群中，资源质量对疾病进化结果没有影响。然而，当存在局部相互作用时，对于线性和饱和的传播 - 毒力权衡假设，较高的资源质量通常会选择更高的毒力/传播率。例外情况是，在阉割型寄生虫（即受感染宿主无繁殖能力）中，在局部和全局混合感染情况下，无论资源质量高低，都会选择更高的毒力。环境资源分布的异质性仅对阉割型寄生虫的结果有影响，随机分布通常会选择更高的毒力。总体而言，我们的结果进一步强调了考虑空间结构对于理解进化过程的重要性。
