Despite the wide distribution of many parasites around the globe, the range of individual species varies significantly, even among phylogenetically related taxa. Given that parasites need suitable hosts to complete their development, parasite geographical and environmental ranges should be limited to communities where their hosts are found. Parasites might also suffer from a trade-off between being locally abundant or widely dispersed. We hypothesize that the geographical and environmental ranges of parasites are negatively associated with their host specificity and their local abundance.

中文翻译：

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宿主或本地专业化的对比效应：广泛分布的血孢子虫是宿主通才，而本地专家在本地很丰富

尽管许多寄生虫在全球范围内分布广泛，但个体物种的范围差异很大，即使在系统发育相关的分类群中也是如此。鉴于寄生虫需要合适的宿主来完成其发育，寄生虫的地理和环境范围应限于发现宿主的社区。寄生虫也可能在局部丰富或广泛分布之间进行权衡。我们假设寄生虫的地理和环境范围与其宿主特异性和当地丰度呈负相关。