Hare Kelly M, Daugherty Charles H, Chapple David G
Allan Wilson Centre for Molecular Ecology and Evolution, School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6140, New Zealand.
Mol Phylogenet Evol. 2008 Jan;46(1):303-15. doi: 10.1016/j.ympev.2007.08.012. Epub 2007 Aug 31.
Sea-level fluctuations during the Pliocene and Pleistocene have shaped the landscape of the Northland region of New Zealand. We examined the comparative phylogeography of three skink species (Oligosoma moco, O. smithi, O. suteri) in northeastern New Zealand in order to investigate the impact of the historical processes that have prevailed since the Pliocene on the Northland fauna. O. moco, O. smithi and O. suteri have similar distributions across northeastern New Zealand, frequently occurring in sympatry. We obtained sequence data from across the entire range of each species, targeting the ND2 mitochondrial gene. Using Neighbor-Joining, Maximum likelihood and Bayesian methods, our analysis revealed contrasting phylogeographic patterns in each species. We found substantial phylogeographic structure within O. moco, with three distinct clades identified. Similarly, deep phylogeographic divergence was evident within O. smithi, with three distinct clades present. Clade 1 included O. smithi populations from the Three Kings Islands and the western coastline of Northland, while Clade 2 encompassed the remainder of the range. However, since Clade 3 corresponded to a described species (O. microlepis), O. smithi might represent a species complex. In both O. moco and O. smithi, divergences among clades are estimated to have occurred in the Pliocene, with divergences within clades occurring during the Pleistocene. In contrast, genetic divergence among O. suteri populations was extremely limited and indicative of more recent divergences during the Pleistocene. The lack of phylogeographic structure in O. suteri might be a consequence of its oviparous reproductive mode, which restricted its distribution to warm northern refugia during glacial maxima. Differences in the ecology and biology of each species might have produced contrasting responses to the same historical processes, and ultimately diverse phylogeographic patterns. Our study reveals an absence of consistent and concordant phylogeographic patterns in the Northland biota, even within the same taxonomic group.
上新世和更新世期间的海平面波动塑造了新西兰北国地区的地貌。我们研究了新西兰东北部三种石龙子物种（莫氏寡鳞蜥、史密斯寡鳞蜥、苏特氏寡鳞蜥）的比较系统地理学，以调查自上新世以来盛行的历史过程对北国动物群的影响。莫氏寡鳞蜥、史密斯寡鳞蜥和苏特氏寡鳞蜥在新西兰东北部有相似的分布，经常同域出现。我们针对每个物种的整个分布范围获取了序列数据，目标是线粒体 ND2 基因。使用邻接法、最大似然法和贝叶斯方法，我们的分析揭示了每个物种截然不同的系统地理格局。我们在莫氏寡鳞蜥中发现了显著的系统地理结构，识别出三个不同的分支。同样，史密斯寡鳞蜥内部也有明显的深度系统地理分化，存在三个不同的分支。分支 1 包括来自三王群岛和北国西部海岸线的史密斯寡鳞蜥种群，而分支 2 涵盖了该分布范围的其余部分。然而，由于分支 3 对应于一个已描述的物种（小鳞寡鳞蜥），史密斯寡鳞蜥可能代表一个物种复合体。在莫氏寡鳞蜥和史密斯寡鳞蜥中，各分支之间的分化估计发生在上新世，各分支内部的分化发生在更新世。相比之下，苏特氏寡鳞蜥种群之间的遗传分化极其有限，表明在更新世期间有更近的分化。苏特氏寡鳞蜥缺乏系统地理结构可能是其卵生繁殖模式的结果，这种模式在冰川最大值期间将其分布限制在温暖的北部避难所。每个物种生态和生物学的差异可能对相同的历史过程产生了截然不同的反应，并最终形成了多样的系统地理格局。我们的研究表明，即使在同一分类群内，北国生物群中也不存在一致和协调的系统地理格局。
