Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Illinois 61820.
Program in Ecology, Evolution, and Conservation Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820.
Evolution. 2018 Jan;72(1):95-112. doi: 10.1111/evo.13386. Epub 2017 Nov 24.
Parasite diversity accounts for most of the biodiversity on earth, and is shaped by many processes (e.g., cospeciation, host switching). To identify the effects of the processes that shape parasite diversity, it is ideal to incorporate both deep (phylogenetic) and shallow (population) perspectives. To this end, we developed a novel workflow to obtain phylogenetic and population genetic data from whole genome sequences of body lice parasitizing New World ground-doves. Phylogenies from these data showed consistent, highly resolved species-level relationships for the lice. By comparing the louse and ground-dove phylogenies, we found that over long-term evolutionary scales their phylogenies were largely congruent. Many louse lineages (both species and populations) also demonstrated high host-specificity, suggesting ground-dove divergence is a primary driver of their parasites' diversity. However, the few louse taxa that are generalists are structured according to biogeography at the population level. This suggests dispersal among sympatric hosts has some effect on body louse diversity, but over deeper time scales the parasites eventually sort according to host species. Overall, our results demonstrate that multiple factors explain the patterns of diversity in this group of parasites, and that the effects of these factors can vary over different evolutionary scales. The integrative approach we employed was crucial for uncovering these patterns, and should be broadly applicable to other studies.
寄生虫多样性构成了地球上大部分的生物多样性，并且受到许多过程的影响（例如共进化、宿主转换）。为了确定影响寄生虫多样性形成的过程的影响，最好同时结合深度（系统发育）和浅层（种群）的观点。为此，我们开发了一种新的工作流程，从寄生在新世界地雀身上的体虱的全基因组序列中获取系统发育和种群遗传数据。这些数据的系统发育分析显示了虱子高度一致、分辨率很高的种级关系。通过比较虱子和地雀的系统发育树，我们发现它们的系统发育在长期进化尺度上基本一致。许多虱子谱系（包括物种和种群）也表现出高度的宿主特异性，这表明地雀的分化是它们寄生虫多样性的主要驱动因素。然而，少数作为广宿主种的虱子分类群是根据种群水平的生物地理学结构的。这表明在共生宿主之间的扩散对体虱的多样性有一定的影响，但在更深的时间尺度上，寄生虫最终会根据宿主物种进行分类。总体而言，我们的研究结果表明，多种因素解释了这组寄生虫的多样性模式，而这些因素的影响在不同的进化尺度上可能会有所不同。我们采用的综合方法对于揭示这些模式至关重要，并且应该广泛适用于其他研究。
