Collaborative Research: Coevolution of Hosts and Parasitoids within a Geographic Mosaic

共同进化--相互作用的物种经历相互进化变化的过程--是生物多样性产生和维持的主要驱动力之一。过去十年的研究表明，空间异质性可以影响共同进化的相互作用。然而，仍然需要对空间异质性对共同进化的影响有一个完整的、机械性的理解。这项研究结合了理论和实证方法，严格评估资源可用性的空间异质性和栖息地斑块之间的分散性如何影响共同进化。它利用大肠杆菌和噬菌体T7(大肠杆菌的一种病毒寄生蜂)作为共同进化的模式生物。直接操纵扩散和资源可获得性的实验将与包含寄主-寄生蜂相互作用细节的理论模型相结合，以提供跨异质景观的扩散如何影响共同进化的定性和定量预测。这项研究在当前数学模型的相对简单性和实地研究的复杂性之间提供了一个至关重要的中间地带。这项研究将增加我们对共同进化的地理镶嵌理论和元群落理论的理解，这两个理论是保护生物学中关于栖息地碎片化的许多工作的基础。这项工作还将增加我们对共同进化微生物的理解，这些微生物发挥着许多关键的生态系统服务，而对它们的研究一直很少。最后，这项研究将有助于我们对空间异质性如何影响相互作用的有机体的生态和进化的一般知识。

Coevolution - the process by which interacting species undergo reciprocal evolutionary change - is one of the major driving forces underlying the generation and maintenance of biodiversity. Research over the past decade has shown that spatial heterogeneity can influence coevolutionary interactions. However, a complete, mechanistic understanding of the influence of spatial heterogeneity on coevolution is still needed. The proposed research combines theoretical and empirical approaches to rigorously evaluate how spatial heterogeneity in resource availability and dispersal among habitat patches influence coevolution. It utilizes the bacterium Escherichia coli and the bacteriophage T7, a viral parasitoid of E. coli, as model coevolving organisms. Experiments in which dispersal and resource availability are directly manipulated will be combined with theoretical models that incorporate details of the host-parasitoid interaction to provide both qualitative and quantitative predictions of how dispersal across a heterogeneous landscape influences coevolution. This research provides a crucial middle ground between the relative simplicity of current mathematical models and the complexity of field studies. This research will add to our understanding of the geographic mosaic theory of coevolution and metacommunity theory, which underlie much of the work on habitat fragmentation in conservation biology. This work will also increase our understanding of coevolving microbes, which perform many crucial ecosystem services and which have been vastly understudied. Finally, the research will contribute to our general knowledge of how spatial heterogeneity influences the ecology and evolution of interacting organisms.