Smith T B, Holder K, Girman D, O'Keefe K, Larison B, Chan Y
Center for Tropical Research and Department of Biology, San Francisco State University, San Francisco CA 94132, USA.
Mol Ecol. 2000 Oct;9(10):1505-16. doi: 10.1046/j.1365-294x.2000.01032.x.
We illustrate the use of Faith's 'Phylogenetic Diversity' measure to compare the phylogeographic structure of two bird species with patterns of avian endemism across six mountains in Cameroon and Equatorial Guinea. The Mountain Greenbul and Cameroon Blue-headed Sunbird showed phylogeographic patterns that together defined three biogeographic regions: Bioko, Mt. Cameroon, and the northern mountains of Cameroon. In contrast, the distributions of endemic species were largely a function of geographical distance, with close mountains sharing more endemic species than distant mountains. Moreover, for both species, populations on Mt. Cameroon were distinctive with respect to the ecologically relevant character bill size. Our results, while preliminary, illustrate the utility of a comparative approach for identifying geographical regions that harbour evolutionarily distinct populations and caution against using only the distributional patterns of endemics to prioritize regions for conservation. Results show that patterns of endemism may not be concordant with patterns of phylogenetic diversity nor morphological variation in a character important in fitness. While incorporation of additional species from unrelated taxa will be necessary to draw definitive conclusions about evolutionarily distinct regions, our preliminary results suggest a conservation approach for the Afromontane region of the Gulf of Guinea that would: (i) emphasize protection of both Bioko and Mt. Cameroon, thereby maximizing preservation of within-species phylogenetic and morphologic diversity; (ii) emphasize protection within the northern mountains to further conserve intraspecific phylogenetic diversity and maximize protection of endemic species.
我们阐述了使用费思的“系统发育多样性”指标，将两种鸟类的系统地理学结构与喀麦隆和赤道几内亚六座山脉的鸟类特有模式进行比较。山地绿鹃和喀麦隆蓝头太阳鸟呈现出系统地理学模式，共同界定了三个生物地理区域：比奥科岛、喀麦隆山以及喀麦隆北部山脉。相比之下，特有物种的分布在很大程度上是地理距离的函数，距离较近的山脉比距离较远的山脉共享更多特有物种。此外，对于这两个物种而言，喀麦隆山的种群在与生态相关的喙大小特征方面具有独特性。我们的结果虽然是初步的，但说明了一种比较方法在识别拥有进化上不同种群的地理区域方面的效用，并告诫不要仅使用特有物种的分布模式来确定保护区域的优先级。结果表明，特有模式可能与系统发育多样性模式以及对适应性很重要的一个特征的形态变异不一致。虽然纳入来自不相关分类群的更多物种对于得出关于进化上不同区域的明确结论是必要的，但我们的初步结果为几内亚湾的阿非利加山地地区提出了一种保护方法，该方法将：（i）强调对比奥科岛和喀麦隆山两者的保护，从而最大限度地保护物种内的系统发育和形态多样性；（ii）强调在北部山脉内的保护，以进一步保护种内系统发育多样性并最大限度地保护特有物种。
