Brower Andrew V Z, de Pinna Mario C C
Evolution and Ecology Group, Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
Museu de Zoologia da Universidade de São Paulo, Av. Nazaré 481, São Paulo, SP, 04263-000, Brazil.
Cladistics. 2014 Jun;30(3):330-336. doi: 10.1111/cla.12050. Epub 2013 Aug 19.
In light of recent terminological controversy, this article reviews cladistic conceptions of character states coded as absences, symplesiomorphies, and secondary losses. The first section addresses absence as a question of ontology vs. epistemology. The second and third sections address the evidentiary status of symplesiomorphy in cladistics, the fourth contrasts primitive absence with secondary loss, and the fifth clarifies the meaning of "grouping". While secondary losses (reversals) are often synapomorphies, symplesiomorphies ("absent" or otherwise) have no evidentiary import to cladistic hypotheses of relationship. Thus, we argue that identifying symplesiomorphic character states as "homologous" is conceptually vacuous, because they are either synapomorphies (homologues) of more inclusive taxa, or complementary absences that unite no group.
鉴于近期的术语争议，本文回顾了编码为缺失、同祖征和次生损失的性状状态的分支概念。第一部分将缺失作为本体论与认识论的问题进行探讨。第二和第三部分讨论了同祖征在分支分类学中的证据地位，第四部分对比了原始缺失与次生损失，第五部分阐明了“分组”的含义。虽然次生损失（逆转）通常是共衍征，但同祖征（“缺失”或以其他方式）对分支关系假说没有证据意义。因此，我们认为将同祖性状状态识别为“同源”在概念上是空洞的，因为它们要么是更具包容性的分类群的共衍征（同源物），要么是不联合任何类群的互补缺失。
