Data from: Integrating phylogenetic and ecological distances reveals new insights into parasite host specificity

The range of hosts a pathogen infects (host specificity) is a key element
of disease risk that may be influenced by both shared phylogenetic history
and shared ecological attributes of prospective hosts. Phylospecificity
indices quantify host specificity in terms of host relatedness, but can
fail to capture ecological attributes that increase susceptibility. For
instance, similarity in habitat niche may expose phylogenetically
unrelated host species to similar pathogen assemblages. Using a recently
proposed method that integrates multiple distances, we assess the relative
contributions of host phylogenetic and functional distances to pathogen
host specificity (functional–phylogenetic host specificity). We apply this
index to a data set of avian malaria parasite (Plasmodium and Haemoproteus
spp.) infections from Melanesian birds to show that multihost parasites
generally use hosts that are closely related, not hosts with similar
habitat niches. We also show that host community phylogenetic ß-diversity
(Pßd) predicts parasite Pßd and that individual host species carry
phylogenetically clustered Haemoproteus parasite assemblages. Our findings
were robust to phylogenetic uncertainty, and suggest that phylogenetic
ancestry of both hosts and parasites plays important roles in driving
avian malaria host specificity and community assembly. However,
restricting host specificity analyses to either recent or historical
timescales identified notable exceptions, including a ‘habitat specialist’
parasite that infects a diversity of unrelated host species with similar
habitat niches. This work highlights that integrating ecological and
phylogenetic distances provides a powerful approach to better understand
drivers of pathogen host specificity and community assembly.

病原体所能感染的宿主范围（宿主特异性，host specificity）是疾病风险的核心要素，其可能同时受到潜在宿主共有的系统发育历史与共享生态特征的影响。系统发育特异性指数（phylospecificity indices）以宿主亲缘关系为依据量化宿主特异性，但无法捕捉会提升宿主易感性的生态特征。例如，栖息地生态位的相似性可能使系统发育关系较远的宿主物种接触到相似的病原体类群。本研究采用近期提出的整合多重距离的方法，评估宿主系统发育距离与功能距离对病原体宿主特异性（功能-系统发育宿主特异性，functional–phylogenetic host specificity）的相对贡献。我们将该指数应用于一套源自美拉尼西亚鸟类的禽疟原虫（疟原虫属*Plasmodium*、血变原虫属*Haemoproteus* spp.）感染数据集，结果显示多宿主寄生虫通常倾向于感染亲缘关系较近的宿主，而非栖息地生态位相似的宿主。研究还发现，宿主群落系统发育β多样性（Pßd）可预测寄生虫群落的系统发育β多样性（Pßd），且单个宿主物种携带的血变原虫类群呈现系统发育聚集特征。本研究结果对系统发育不确定性具有稳健性，表明宿主与寄生虫的系统发育祖先均在驱动禽疟原虫宿主特异性及群落构建中发挥重要作用。然而，若将宿主特异性分析限定于近期或历史时间尺度，则可发现显著的例外案例，例如一类“栖息地特化”的寄生虫，其可感染多种生态位相似但亲缘关系较远的宿主物种。本研究凸显出整合生态距离与系统发育距离，是解析病原体宿主特异性及群落构建驱动机制的有效手段。