Data from: Patterns of specificity of the pathogen Escovopsis across the fungus-growing ant symbiosis

Parasites evolve within complex abiotic and biotic environments. Because of this, it is often challenging to ascertain how evolutionary and ecological processes together affect parasite specialization. Here, we use the fungus-growing ant system, which consists of ancient, likely coevolved, complex communities, to explore the ecological and evolutionary forces shaping host-parasite specificity. We use a comparative phylogenetic framework to determine whether patterns of specificity between the fungal parasite Escovopsis and its host fungi at fine phylogenetic scales reflect patterns of specificity at broader phylogenetic levels. In other words, we ask whether parasite specificity across broad host phylogenetic relationships is maintained by specificity toward more closely related hosts. We couple this exploration with manipulations of the community context within which host-parasite interactions are taking place to evaluate how community complexity alters parasite specificity. Regardless of host community complexity, parasites displayed a consistent pattern of specialization on native hosts, that is, those that they are found attacking in nature, with the potential for occasional switching to hosts distantly related to their native hosts. These results suggest that, even within a complex community context, pairwise host and parasite adaptation and coadaptation can be the primary drivers of the evolution and maintenance of parasite specificity.寄生物在复杂的非生物与生物环境中演化。正因如此，厘清进化与生态过程如何共同影响寄生物专化性，往往颇具挑战。本研究以由古老且大概率存在共演化关系的复杂群落构成的植菌蚂蚁系统为研究对象，探究塑造宿主-寄生物专化性（host-parasite specificity）的生态与进化力量。本研究采用比较系统发育框架（comparative phylogenetic framework），以探究真菌寄生物Escovopsis与其宿主真菌在精细系统发育尺度下的专化模式，是否能反映宽泛系统发育尺度下的专化模式。换言之，本研究旨在探讨：跨宽泛宿主系统发育关系的寄生物专化性，是否由针对亲缘关系更近宿主的专化性所维系。本研究同时结合宿主-寄生物相互作用所处群落背景的操控实验，以评估群落复杂性如何改变寄生物专化性。无论宿主群落复杂性如何，寄生物均表现出对本地宿主（即野外环境中其实际侵染的宿主）的稳定专化模式，且偶尔存在向与本地宿主亲缘关系较远的宿主转换的可能性。上述结果表明，即便处于复杂的群落背景中，宿主与寄生物间的两两适应性演化与共适应性演化，仍可作为寄生物专化性演化与维持的核心驱动力。