Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9 Canada.
Mol Phylogenet Evol. 2010 Apr;55(1):18-25. doi: 10.1016/j.ympev.2010.01.015. Epub 2010 Jan 25.
The interpretation of a group's evolutionary history can be altered based on the phylogenetic placement of problematic taxa. Mountain goats (Oreamnos americanus) epitomize a 'rogue taxon' as many placements within the Caprini tribe have been suggested. Using a total evidence approach, we reconstructed the Caprini phylogeny using parsimony, likelihood, and Bayesian methods. Bayesian and likelihood methods placed mountain goats as an independent lineage sister to all Caprini except muskox and goral. Maximum parsimony placed mountain goats in a derived Caprini clade. Closer examination revealed that parsimony analysis failed to integrate over phylogenetic uncertainty. We then tested our mountain goat placement against nine published alternatives using non-parametric tests, and the parametric SOWH test. Non-parametric tests returned ambiguous results, but the SOWH test rejected all alternative hypotheses. Our study represents the first explicit testing of all hypotheses for the placement of mountain goats and supports a relatively basal position for the taxon.
基于有问题分类单元的系统发育位置，群体的进化历史解释可能会发生改变。许多研究都表明，野山羊（Oreamnos americanus）是“流氓分类单元”的典型代表。本研究采用总证据法，利用简约法、似然法和贝叶斯法重建了 Caprini 进化枝的系统发育关系。贝叶斯法和似然法将野山羊置于一个独立的支系中，与除麝香牛和扭角羚以外的所有 Caprini 支系为姐妹群。最大简约法将野山羊置于一个衍生的 Caprini 分支中。进一步的分析表明，简约法分析未能整合系统发育不确定性。然后，我们使用非参数检验和参数化的 SOWH 检验，针对 9 种已发表的替代方案，对野山羊的放置位置进行了检验。非参数检验的结果模棱两可，但 SOWH 检验拒绝了所有替代假设。本研究首次明确地检验了野山羊放置位置的所有假设，支持该分类单元相对基础的位置。
