Museo de Zoología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre y Roca, Aptdo. 17-01-2184, Quito, Ecuador.
Mol Phylogenet Evol. 2012 Dec;65(3):805-22. doi: 10.1016/j.ympev.2012.08.001. Epub 2012 Aug 21.
As Darwin observed, the differentiation among varieties, subspecies, and species seems, often times, arbitrary. Nowadays, however, novel tools provide the possibility of testing hypotheses of species. Using the Andean toad genus Osornophryne, we address the following questions: (1) How many species are within the genus? (2) Are morphological and molecular traits congruent when delimiting species? (3) Which morphological traits are the most divergent among species? We use recently developed methods for testing species boundaries and relationships using a multilocus data set consisting of two mitochondrial genes (12S, 16S; 1647bp aligned matrix), one exon (RAG-1; 923 aligned matrix), and one intron (RPL3Int5; 1410bp aligned matrix). As another line of evidence for species delimitation, we integrated analyses of 12 morphometric variables and 10 discrete traits commonly used in amphibian systematics. The molecular and morphological approaches support the validity of most of the described species in Osornophryne. We find, however, contradictory lines of evidence regarding the status of O. angel. Within O. guacamayo, we found a genetically divergent population that, we argue, represents a new species. We consider that O. bufoniformis represents a species complex that deserves further study. We highlight the importance of incorporating morphological data when delimiting species, especially for lineages that have a recent origin and have not achieved reciprocal monophyly in molecular phylogenies. Finally, the most divergent morphological traits among Osornophryne species are associated with locomotion (finger, toes and limbs) and feeding (head), suggesting an association between morphology and the ecological habits of the species.
正如达尔文所观察到的，品种、亚种和物种之间的分化似乎常常是任意的。然而，如今新的工具为测试物种假说提供了可能性。我们利用安第斯蟾蜍属 Osornophryne 来解决以下问题：(1) 属内有多少个物种？(2) 在划定物种时，形态和分子特征是否一致？(3) 物种之间哪些形态特征差异最大？我们使用最近开发的方法，使用包含两个线粒体基因（12S、16S；1647bp 对齐矩阵）、一个外显子（RAG-1；923bp 对齐矩阵）和一个内含子（RPL3Int5；1410bp 对齐矩阵）的多基因数据集来测试物种边界和关系。作为物种划定的另一种证据，我们整合了 12 个形态变量和 10 个常用于两栖动物系统发育的离散特征的分析。分子和形态方法支持 Osornophryne 中大多数描述物种的有效性。然而，我们发现关于 O. angel 地位的证据相互矛盾。在 O. guacamayo 中，我们发现了一个遗传上有差异的种群，我们认为这代表了一个新物种。我们认为 O. bufoniformis 代表一个值得进一步研究的物种复合体。我们强调在划定物种时纳入形态数据的重要性，特别是对于那些起源较近且在分子系统发育中尚未达到相互单系性的谱系。最后，Osornophryne 物种之间形态差异最大的特征与运动（手指、脚趾和四肢）和进食（头部）有关，这表明形态与物种的生态习性之间存在关联。
