Rieppel Olivier
Rowe Family Curator of Evolutionary Biology, Negaunee Integrative Research Center, The Field Museum, Chicago, IL, 60605-2496, USA.
J Hist Biol. 2020 Jun;53(2):217-230. doi: 10.1007/s10739-020-09600-x.
The concept that renders morphology a tool for phylogeny reconstruction is homology. The concept of homology is rooted in pre-evolutionary idealistic morphology. The claim that the goal of idealistic morphology was the seriability of form may sound paradoxical given that this discipline proceeded within a framework of strictly delimited types. But the types only demarcate where seriability starts and where it comes to an end. Carl Gegenbaur's (Grundzüge der vergleichenden Anatomie, Wilhelm Engelmann, Leipzig, 1859) was recognized as a milestone in idealistic morphology. A comparison with the second edition of 1870 illustrates Gegenbaur's turn to evolutionary morphology. The methodology remained the same-seriability of form-but the series was no longer merely descriptive or conceptual but now a historical, evolutionary one. Gegenbaur emphasized that seriability of form was possible not only between species of the same type, but also between parts (organs) of organisms of the same type. Pursuing this project, he found that different parts of organisms evolve at different rates, resulting in an incongruence between the series of parts (organs) relative to the series of species under comparison. This incongrence was called chevauchement des spécialisations by Louis Dollo, Spezialisationskreuzungen by Othenio Abel, and heterobathmy of characters by Armen Takhtajan. Willi Hennig, the founder of modern methods in phylogenetic systematics, discovered that the heterobathmy of characters was a precondition for the establishment of the phylogenetic relationships based on shared derived characters. The result was a replacement of the search for ancestors by a search for relative degrees of phylogenetic relationships (sister-group relationships).
使形态学成为系统发育重建工具的概念是同源性。同源性概念植根于进化前的唯心主义形态学。鉴于这一学科是在严格界定的类型框架内进行的，唯心主义形态学的目标是形式的序列化这一说法可能听起来自相矛盾。但这些类型只是划定了序列化从何处开始以及在何处结束。卡尔· Gegenbaur（《比较解剖学基础》，威廉·恩格尔曼，莱比锡，1859年）被认为是唯心主义形态学的一个里程碑。与1870年的第二版进行比较，可以说明Gegenbaur向进化形态学的转变。方法仍然相同——形式的序列化——但这个序列不再仅仅是描述性的或概念性的，而是现在的历史性、进化性的序列。Gegenbaur强调，形式的序列化不仅在同一类型的物种之间是可能的，而且在同一类型生物体的各个部分（器官）之间也是可能的。在推进这个项目的过程中，他发现生物体的不同部分以不同的速度进化，导致所比较的部分（器官）序列相对于物种序列之间出现不一致。这种不一致被路易·多洛称为“特化的交叉”，被奥泰尼奥·阿贝尔称为“特化杂交”，被阿尔缅·塔赫塔江称为“性状的异时性”。现代系统发育系统学方法的创始人威利·亨尼希发现，性状的异时性是基于共同衍生性状建立系统发育关系的一个前提条件。结果是将寻找祖先的过程替换为寻找系统发育关系的相对程度（姐妹群关系）。
