Evolutionary ecology of parasite-host species interactions

寄生虫-宿主物种相互作用的进化生态学：宿主物种利用、抗性进化和寄生虫聚集。关于寄生虫和它们的宿主物种的共同进化相互作用已经有了很多研究。也就是说，研究人员经常感兴趣的问题是，为什么一些寄生虫和病原体物种是令人讨厌的，而另一些相对良性；或者，为什么一些寄生虫或病原体物种具有广泛的宿主物种范围，而其他寄生虫或病原体物种在其生命周期的特定阶段往往是专门的。由于不对称选择，寄生虫和病原体通常被认为在进化上比宿主占上风。这是因为寄生虫和病原体的繁殖周期往往比它们的宿主短，感染阶段的数量比它们的宿主多得多，并且它们的生长、发育和/或繁殖对宿主个体有一定的依赖性。然而，这种观点掩盖了寄生虫经常与其他物种共享宿主资源的事实，而且许多寄生虫物种有几个宿主物种，即使在同一个地点和同一时间段。同时存在的多宿主、多寄生虫关联为寄生虫及其宿主之间的扩散生态和进化相互作用奠定了基础。这种分散的相互作用在自然界中很可能是常见的，但相对来说却很少受到关注。在本应用程序中，我将概述一些关于寄生和寄主抗性的种内和种间变异及其与寄主物种生态学和寄主物种范围的关系的更突出的假设。我的实验室在研究不同种类的蜻蜓和它们的外寄生螨来验证这些假设方面有着丰富的传统。在我的HQP中，我还将讨论寄生虫在宿主物种上聚集的进化原因和重要性，这被认为是生态寄生虫学的一般规律之一，并且对寄生虫之间的种内和种间相互作用具有影响。随着条形码技术的出现，以前认为困难的实验方法，物种相互作用的地理比较，以及基于经验结果的基于方程的模型的出现，测试和见解变得更加强大，所有这些都是为本拨款周期提出的方法。样品制备和分类是在我的实验室完成的；安大略省生物多样性研究所和AgCan的合作者可以进行条形码。实验方法有可能与cfi资助的环境室和NSERC rti资助的蔡司显微镜和Conviron孵化器。我们为地理研究选择了地点，我们有基于方程的建模方面的专业知识。学生从我、其他HQP和合作者那里得到有效的训练，掌握一到几种实验和统计技术。（详见CCV，提案和随附的贡献）。

Evolutionary ecology of parasite-host species interactions: host species use, evolution of resistance, and parasite aggregation.Much ink has been spilled about co-evolutionary interactions of parasites and their host species. That is, researchers are often interested in questions such as why some parasites and pathogen species are nasty, whereas others are relatively benign; or, why some parasites or pathogen species have broad host species ranges whereas others tend to be specialists, for a given stage of their life cycle. Parasites and pathogens are often seen as having the evolutionary upper hand over their hosts because of asymmetric selection. This is because parasites and pathogens often have shorter generation times than their hosts, have infective stages that are much more numerous than their hosts, and have an obligate dependence on host individuals for their growth, development and/or reproduction. However, this view belies the facts that parasites often share host resources with other species and also that many parasite species have several host species, even at single sites and over the same time frames. Concurrent multi-host, multi-parasite associations set the stage for diffuse ecological and evolutionary interactions amongst parasites and their hosts. Such diffuse interactions are likely common in nature, yet have received comparatively little attention. In this application, I will outline some of the more prominent hypotheses about intra- and interspecific variation in parasitism and host resistance and its relation to ecology of host species and host species range of parasitic organisms. My lab has a rich tradition in studying various species of dragonflies and their ectoparasitic mites to test such hypotheses. With my HQP, I will also address the evolutionary causes and importance of parasite aggregation on host species, which is deemed one of the general laws of ecological parasitology and which has implications for intra-and interspecific interactions among parasites. Tests and insights have become much stronger with the following: the advent of barcoding techniques, experimental approaches previously deemed difficult, geographical comparisons of species interactions, and equation-based models building on empirical results, all of which are proposed approaches for this grant cycle. Sample preparation and taxonomy is done in my lab; collaborators at Biodiversity Institute of Ontario and AgCan do barcoding. Experimental approaches are possible with CFI-funded Environmental Rooms and NSERC RTI-funded Zeiss microscope and Conviron incubators. We have sites chosen for the geographical studies and we have expertise with equation-based modeling. Students gain effective training from me, other HQP and collabotators with one to several experimental and statisitical techniques. (See CCV, Proposal and Attached Contributions for details).