Host and habitat specialization of avian malaria in Africa.
Host and habitat specialization of avian malaria in Africa.
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DOI：
10.1111/j.1365-294x.2011.05341.x
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发表时间：
2012-01
影响因子：
4.9
通讯作者：
Sehgal RN
中科院分区：
文献类型：
--
作者：
Loiseau C;Harrigan RJ;Robert A;Bowie RC;Thomassen HA;Smith TB;Sehgal RN
对脊椎动物和无脊椎动物的研究表明，与通才相比，专家可能会因环境变化而遭受更严重的衰退。关于环境条件对专家与通才寄生虫的影响知之甚少。在这里，我们研究疟疾寄生虫（疟原虫属）的进化策略。在不同的鸟类宿主群落中。我们确定了寄生虫的多样性和流行的禽疟疾在三个鸟类社区的低地森林在喀麦隆，在东非的高地森林，在南非的fynbos。我们计算了寄生虫的宿主特异性指数，以检查作为栖息地的函数寄生的宿主范围，并调查了寄生虫的系统发育关系。首先，使用系统发育和祖先重建分析，我们发现了一个进化的趋势，通才疟疾寄生虫成为专家。通才成为专家的转化率几乎是专家成为通才的转化率的四倍。我们还发现更多的专业寄生虫和更大的寄生虫多样性在非洲低地雨林相比，气候更多变的栖息地的fynbos和高地森林。因此，随着环境的变化，我们预计专家和通才寄生虫分布的变化，对鸟类群落的潜在影响。
Studies of both vertebrates and invertebrates have suggested that specialists, as compared to generalists, are likely to suffer more serious declines in response to environmental change. Less is known about the effects of environmental conditions on specialist vs. generalist parasites. Here, we study the evolutionary strategies of malaria parasites (Plasmodium spp.) among different bird host communities. We determined the parasite diversity and prevalence of avian malaria in three bird communities in the lowland forests in Cameroon, highland forests in East Africa, and fynbos in South Africa. We calculated the host specificity index of parasites to examine the range of hosts parasitized as a function of the habitat, and investigated the phylogenetic relationships of parasites. First, using phylogenetic and ancestral reconstruction analyses we found an evolutionary tendency for generalist malaria parasites to become specialists. The transition rate at which generalists become specialists was nearly four times as great as the rate at which specialists become generalists. We also found more specialist parasites and greater parasite diversity in African lowland rainforests as compared to the more climatically variable habitats of the fynbos and the highland forests. Thus, with environmental changes, we anticipate a change in the distribution of both specialist and generalist parasites with potential impacts on bird communities.