Friesen V L, Anderson D J
Department of Biology, Queen's University, Kingston, Ontario, Canada.
Mol Phylogenet Evol. 1997 Apr;7(2):252-60. doi: 10.1006/mpev.1996.0397.
Although the allopatric model of speciation is widely accepted, it does not provide a satisfactory explanation for many evolutionary phenomena. Several alternative models exist, but they remain largely untested for vertebrate animals. In the present paper, a molecular phylogeny was used to test competing models of speciation in a seabird family, the Sulidae. A segment including 807 base pairs of the mitochondrial cytochrome b gene was sequenced from all extant sulid species, and phylogenetic methods were used to test model-specific predictions regarding tree topologies, distributions of sister taxa, timing of vicariant events, and comparative biology. Both the neighbor-joining and parsimony analyses placed sequences of gannets (Morus spp.) and boobies of the genus Sula in separate, monophyletic lineages. Sequences of Cape (M. capensis) and Australasian (M. serrator) gannets clustered together, and the sequence of Abbott's booby (Papasula abbotti) was basal to those of the gannets. Sequences of blue-footed (S. nebouxii) and Peruvian (S. variegata) boobies were sisters and formed a monophyletic group with the masked booby (S. dactylatra). The red-footed booby (S. sula) sequence was the most divergent of the Sula boobies. All relationships received strong support from standard-error tests and bootstrap analysis. Substitution rates were similar to those suggested for mammals and suggested that most lineages arose within the last 3 million years. Lineage divergence events for which the mode of speciation could be deduced did not fit the predictions of either allopatric or sympatric models, but apparently involved either peripatric or parapatric processes.
尽管异域物种形成模型被广泛接受，但它并不能为许多进化现象提供令人满意的解释。存在几种替代模型，但在脊椎动物中它们大多仍未得到检验。在本文中，我们使用分子系统发育来检验海鸟科鲣鸟科中相互竞争的物种形成模型。对所有现存鲣鸟物种的线粒体细胞色素b基因的807个碱基对片段进行了测序，并使用系统发育方法来检验关于树形拓扑结构、姐妹类群分布、隔离事件时间以及比较生物学的特定模型预测。邻接法和简约法分析都将鲣鸟属（Morus spp.）的序列和鲣鸟属的鲣鸟置于不同的单系谱系中。南非鲣鸟（M. capensis）和澳新鲣鸟（M. serrator）的序列聚集在一起，阿波特鲣鸟（Papasula abbotti）的序列位于鲣鸟属序列的基部。蓝脚鲣鸟（S. nebouxii）和秘鲁鲣鸟（S. variegata）的序列是姐妹序列，并与褐鲣鸟（S. dactylatra）形成一个单系群。红脚鲣鸟（S. sula）的序列是鲣鸟属中分歧最大的。所有关系都得到了标准误差检验和自展分析的有力支持。替换率与哺乳动物的相似，表明大多数谱系在过去300万年中出现。可以推断物种形成模式的谱系分歧事件并不符合异域或同域模型的预测，但显然涉及边域或邻域过程。
