Origin and radiation of Southern Hemisphere coastal dolphins (genus Cephalorhynchus)
Origin and radiation of Southern Hemisphere coastal dolphins (genus Cephalorhynchus)
复制标题
南半球沿海海豚（头吻海豚属）的起源和辐射
DOI：
10.1046/j.0962-1083.2001.01360.x
复制
发表时间：
2001
影响因子：
4.9
通讯作者：
C. Baker
中科院分区：
文献类型：
--
作者：
F. Pichler;D. Robineau;R. Goodall;M. Meÿer;C. Olivarria;C. Baker
头吻海豚属（Gray 1846）由四种小型沿海海豚组成，分布在南半球的温带冷沃茨。每个物种都与Lissodelphinininae亚科的其他成员同域，但与其他同源物广泛分离。为了描述这些物种的起源和辐射，我们研究了442 bp的线粒体DNA控制区序列的307个个体的属头吻鱼，并比较这些序列从其他成员的亚科Lissodelphinininae。我们调查的假设，Cephalorhynchus是一个单系属，或者，这四个物种分别出现在远洋Lissodelphine物种和收敛形态。我们的研究结果支持单系的头吻内Lissodelphininae和辐射殖民模式。我们证实了模式浅，但可诊断的物种分支与海维赛德的海豚为基础的分支。我们进一步研究了我们的大人口样本为每个物种的母系单倍型的单系性。基于这一独特的地理格局，我们认为头吻龙起源于南非的沃茨，并随着西风漂流，殖民新西兰，然后南美洲。智利海豚和康默森海豚随后在火地岛的冰川作用期间，沿着南美洲的两个海岸沿着形成物种。二次辐射导致Kerguelen岛的Commerson海豚和北岛的Hector海豚在遗传上被隔离。我们的研究结果表明，沿海，深度有限的齿鲸类容易发生种群分裂，隔离和偶尔的长距离迁移，也许是在气候变化之后。
The genus Cephalorhynchus (Gray 1846) consists of four species of small coastal dolphins distributed in cool temperate waters around the Southern Hemisphere. Each species is sympatric with other members of the subfamily Lissodelphininae but widely separated from other congeners. To describe the origin and radiation of these species, we examined 442 bp of mitochondrial DNA control region sequences of 307 individuals from the genus Cephalorhynchus and compared these to sequences from other members of the subfamily Lissodelphininae. We investigate the hypotheses that Cephalorhynchus is a monophyletic genus or, alternatively, that the four species have arisen separately from pelagic Lissodelphine species and have converged morphologically. Our results support the monophyly of Cephalorhynchus within the Lissodelphininae and a pattern of radiation by colonization. We confirm a pattern of shallow but diagnosable species clades with Heaviside’s dolphin as the basal branch. We further examine the monophyly of maternal haplotypes represented by our large population sample for each species. Based on this phylogeographic pattern, we propose that Cephalorhynchus originated in the waters of South Africa and, following the West Wind Drift, colonized New Zealand and then South America. The Chilean and Commerson’s dolphins then speciated along the two coasts of South America, during the glaciation of Tierra del Fuego. Secondary radiations resulted in genetically isolated populations for both the Kerguelen Island Commerson’s dolphin and the North Island Hector’s dolphin. Our results suggest that coastal, depth‐limited odontocetes are prone to population fragmentation, isolation and occasionally long‐distance movements, perhaps following periods of climatic change.