Rees D J, Emerson B C, Oromí P, Hewitt G M
School of Biological Sciences, University of East Anglia, Norwich, UKDepartmento de Zoología, Facultad de Biología, Universidad de La Laguna, La Laguna, Tenerife, Spain.
J Evol Biol. 2001 Jan 8;14(1):139-147. doi: 10.1046/j.1420-9101.2001.00250.x.
The processes of island colonization and speciation are investigated through mtDNA studies on Canary Island beetles. The genus Nesotes (Coleoptera: Tenebrionidae) is represented by 19 endemic species on the Canary Islands, the majority of which are single island endemics. Nesotes conformis is the most widespread, occurring on Gran Canaria, Tenerife, La Palma and El Hierro. Nesotes conformis forms a paraphyletic assemblage, with a split between Gran Canaria and the other three islands. Nesotes conformis of the western Canary Islands cluster with Nesotes altivagans and Nesotes elliptipennis from Tenerife. Fifty-two individuals from this western islands species complex have been sequenced for 675 base pairs of the mtDNA cytochrome oxidase II gene, representing Tenerife, La Palma and El Hierro. A neighbour joining analysis of maximum likelihood distances resulted in three distinct mtDNA lineages for N. conformis, two of which also include mitotypes of N. altivagans and N. elliptipennis. Through application of parametric bootstrap tests, we are able to reject hypotheses of monophyly for both N. conformis and N. altivagans. Nesotes altivagans and N. elliptipennis are poorly separated morphologically and mtDNA sequence data adds support to this being one species with a highly variable morphology. We propose that N. altivagans/N. elliptipennis is recently derived from two ancestral mtDNA lineages within N. conformis from the Teno region of Tenerife. We further propose colonization of the younger islands of La Palma and El Hierro by N. conformis from a mitochondrial lineage within the Teno massif (colonization; diversification; mitochondrial DNA; Canary Islands; Coleoptera).
通过对加那利群岛甲虫的线粒体DNA研究，对岛屿殖民化和物种形成过程进行了调查。Nesotes属（鞘翅目：拟步甲科）在加那利群岛有19个特有物种，其中大多数是单岛特有物种。Nesotes conformis分布最广，出现在大加那利岛、特内里费岛、拉帕尔马岛和耶罗岛。Nesotes conformis形成了一个并系类群，在大加那利岛和其他三个岛屿之间存在分化。加那利群岛西部的Nesotes conformis与特内里费岛的Nesotes altivagans和Nesotes elliptipennis聚类。对来自该西部岛屿物种复合体的52个个体的线粒体DNA细胞色素氧化酶II基因的675个碱基对进行了测序，这些个体分别代表特内里费岛、拉帕尔马岛和耶罗岛。对最大似然距离进行邻接法分析，结果显示N. conformis有三个不同的线粒体DNA谱系，其中两个谱系还包括N. altivagans和N. elliptipennis的线粒体类型。通过应用参数自展检验，我们能够拒绝N. conformis和N. altivagans单系性的假设。Nesotes altivagans和N. elliptipennis在形态上难以区分，线粒体DNA序列数据支持这是一个形态高度可变的物种。我们提出N. altivagans/N. elliptipennis最近源自特内里费岛特诺地区N. conformis内的两个祖先线粒体谱系。我们进一步提出，N. conformis从特诺地块内的一个线粒体谱系对拉帕尔马岛和耶罗岛这些较年轻的岛屿进行了殖民（殖民化；多样化；线粒体DNA；加那利群岛；鞘翅目）。
