Researchers commonly present results of comparative studies of taxonomic groups. In this review we criticize the focus on named clades, usually, comparably ranked groups such as families or orders, for comparative evolutionary analyses and question the general practice of using clades as units of analysis. The practice of analyzing sets of named groups persists despite widespread appreciation that the groups we have chosen to name are based on subjective human concerns rather than objective properties of nature. We demonstrate an effect of clade selection on results in one study, and present some potential alternatives to selecting named clades for analysis that are relatively objective in clade choice. However, we note that these alternatives are only partial solutions for clade-based studies. The practice of analyzing named clades obviously is biased and problematic, but its issues portend broader problems with the general approach of employing clades as units of analysis. We offer an ad-hoc solution to the nonindependence issue but question whether clade-based studies are worthwhile at all when rigorous whole-tree lineage-based methods are available.

中文翻译：

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比较进化研究中进化枝的选择与分析

研究人员通常会展示分类群的比较研究结果。在这篇评论中，我们批评了对命名进化枝的关注，通常，比较排序的群体，如家庭或命令，用于比较进化分析，并质疑使用进化枝作为分析单位的一般做法。尽管人们普遍认为我们选择命名的群体是基于主观的人类关注而不是自然的客观属性，但分析命名群体集的做法仍然存在。我们在一项研究中证明了进化枝选择对结果的影响，并提出了一些潜在的替代方法来选择命名进化枝进行分析，这些进化枝在进化枝选择中相对客观。但是，我们注意到这些替代方案只是基于进化枝的研究的部分解决方案。分析命名进化枝的做法显然是有偏见的和有问题的，但它的问题预示着使用进化枝作为分析单位的一般方法存在更广泛的问题。我们为非独立性问题提供了一个临时解决方案，但质疑当严格的基于全树谱系的方法可用时，基于进化枝的研究是否值得。