Steiner F M, Schlick-Steiner B C, Konrad H, Moder K, Christian E, Seifert B, Crozier R H, Stauffer C, Buschinger A
Department of Integrative Biology, Institute of Zoology, Boku, University of Natural Resources and Applied Life Sciences Vienna, Vienna, Austria.
J Evol Biol. 2006 May;19(3):777-87. doi: 10.1111/j.1420-9101.2005.01053.x.
No aspect of speciation is as controversial as the view that new species can evolve sympatrically, among populations in close physical contact. Social parasitism has been suggested to yield necessary disruptive selection for sympatric speciation. Recently, mitochondrial DNA phylogeography has shown that the ant Myrmica microrubra is closely related to its host, Myrmica rubra, leading to the suggestion that sympatric speciation has occurred. We investigated the relationships between the two ant forms using mitochondrial and nuclear DNA sequences, microsatellite genotyping and morphometrics. Molecular phylogenetic and population structure analyses showed that M. microrubra does not evolve separately to its host but rather shares a gene pool with it. Probability analysis showed that mitochondrial DNA data previously adduced in favour of sympatric speciation do not in fact do so. Morphometrically, M. microrubra is most readily interpreted as a miniature queen form of M. rubra, not a separate species. Myrmica microrubra is not an example of speciation. The large (typical M. rubra) and small (M. microrubra) queen forms are alternative reproductive strategies of the same species. Myrmica microrubraSeifert 1993 is consequently synonymized here with M. rubra Linnaeus, 1758.
物种形成的任何一个方面都没有像新物种可以在紧密物理接触的种群中同域进化这一观点那样具有争议性。社会寄生现象被认为会为同域物种形成产生必要的间断性选择。最近，线粒体DNA系统地理学研究表明，小红蚁（Myrmica microrubra）与其寄主红蚁（Myrmica rubra）密切相关，这引发了同域物种形成已经发生的推测。我们使用线粒体和核DNA序列、微卫星基因分型以及形态测量学方法研究了这两种蚁类形态之间的关系。分子系统发育和种群结构分析表明，小红蚁并没有与其寄主独立进化，而是与其共享一个基因库。概率分析表明，之前用以支持同域物种形成的线粒体DNA数据实际上并不支持这一观点。从形态测量学角度来看，小红蚁最容易被解释为红蚁的一种小型蚁后形态，而非一个独立物种。小红蚁并非物种形成的一个例子。大型（典型的红蚁）和小型（小红蚁）蚁后形态是同一物种的两种交替繁殖策略。因此，这里将1993年由塞弗特定名的小红蚁（Myrmica microrubra）与1758年由林奈定名的红蚁（M. rubra）视为同义词。
