Herron M D, Waterman J M, Parkinson C L
Department of Biology, University of Central Florida, Orlando, FL 32816-2368, USA.
Mol Ecol. 2005 Aug;14(9):2773-88. doi: 10.1111/j.1365-294X.2005.02630.x.
We used phylogenetic and phylogeographical methods to infer relationships among African ground squirrels of the genus Xerus. Using Bayesian, maximum-parsimony, nested clade and coalescent analyses of cytochrome b sequences, we inferred interspecific relationships, evaluated the specific distinctness of Cape (Xerus inauris) and mountain (Xerus princeps) ground squirrels, and tested hypotheses for historical patterns of gene flow within X. inauris. The inferred phylogeny supports the hypothesized existence of an 'arid corridor' from the Horn of Africa to the Cape region. Although doubts have been raised regarding the specific distinctness of X. inauris and X. princeps, our analyses show that each represents a distinct well-supported, monophyletic lineage. Xerus inauris includes three major clades, two of which are geographically restricted. The distributions of X. inauris populations are concordant with divergences within and disjunctions between other taxa, which have been interpreted as results of Plio-Pleistocene climate cycles. Nested clade analysis, coalescent analyses, and analyses of genetic structure support allopatric fragmentation as the cause of the deep divergences within this species.
我们运用系统发育和系统地理学方法来推断旱獭属（Xerus）非洲地松鼠之间的关系。通过对细胞色素b序列进行贝叶斯分析、最大简约法分析、嵌套分支分析和溯祖分析，我们推断种间关系，评估海角地松鼠（Xerus inauris）和山地地松鼠（Xerus princeps）的物种独特性，并检验关于X. inauris内基因流动历史模式的假设。推断出的系统发育支持了从非洲之角到海角地区存在一条“干旱走廊”的假设。尽管有人对X. inauris和X. princeps的物种独特性提出了质疑，但我们的分析表明，它们各自代表一个独特的、得到充分支持的单系谱系。Xerus inauris包括三个主要分支，其中两个在地理上受到限制。X. inauris种群的分布与其他分类群内部的分歧和间断相一致，这些分歧和间断被解释为上新世 - 更新世气候周期的结果。嵌套分支分析、溯祖分析和遗传结构分析支持异域隔离分化是该物种内深度分歧的原因。
