NERC Centre for Population Biology & Division of Biology, Department of Life Sciences, Imperial College London, Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom E-mail:
Evolution. 2012 Mar;66(3):740-751. doi: 10.1111/j.1558-5646.2011.01470.x. Epub 2011 Oct 24.
Host traits, such as migratory behavior, could facilitate the dispersal of disease-causing parasites, potentially leading to the transfer of infections both across geographic areas and between host species. There is, however, little quantitative information on whether variation in such host attributes does indeed affect the evolutionary outcome of host-parasite associations. Here, we employ Leucocytozoon blood parasites of birds, a group of parasites closely related to avian malaria, to study host-parasite coevolution in relation to host behavior using a phylogenetic comparative approach. We reconstruct the molecular phylogenies of both the hosts and parasites and use cophylogenetic tools to assess whether each host-parasite association contributes significantly to the overall congruence between the two phylogenies. We find evidence for a significant fit between host and parasite phylogenies in this system, but show that this is due only to associations between nonmigrant parasites and their hosts. We also show that migrant bird species harbor a greater genetic diversity of parasites compared with nonmigrant species. Taken together, these results suggest that the migratory habits of birds could influence their coevolutionary relationship with their parasites, and that consideration of host traits is important in predicting the outcome of coevolutionary interactions.
宿主特征，如迁徙行为，可以促进致病寄生虫的传播，从而导致感染在地理区域和宿主物种之间转移。然而，关于这些宿主属性的变化是否确实会影响宿主-寄生虫关联的进化结果，定量信息很少。在这里，我们使用鸟类的白细胞寄生虫 Leucocytozoon，一种与禽疟原虫密切相关的寄生虫，来研究与宿主行为相关的宿主-寄生虫共进化，使用系统发育比较方法。我们重建了宿主和寄生虫的分子系统发育，并使用共进化工具来评估每个宿主-寄生虫的关联是否对两个系统发育之间的整体一致性有显著贡献。我们发现这个系统中宿主和寄生虫的系统发育之间存在显著的吻合，但表明这只是由于非迁徙寄生虫与其宿主之间的关联。我们还表明，与非迁徙物种相比，迁徙鸟类物种携带的寄生虫遗传多样性更大。总的来说，这些结果表明鸟类的迁徙习性可能会影响它们与寄生虫的共进化关系，并且考虑宿主特征对于预测共进化相互作用的结果很重要。
