Vanderpoorten A, Jacquemart A-L
Department of Life Sciences, University of Liège, Liège, Belgium.
J Evol Biol. 2004 Mar;17(2):279-87. doi: 10.1111/j.1420-9101.2004.00686.x.
Evolutionary significance of morphological characters that have traditionally been used for species delineation in the aquatic moss genus Amblystegium was tested by partitioning the environmentally and genetically induced morphological variation and focusing on morphological evolution using comparative methods. Cultivation experiments under controlled condition showed that most of the morphological variation in nature resulted from plasticity. Information regarding genetically fixed morphological variation and genetic similarity derived from polymorphic inter-simple sequence repeat markers was combined into an explicit model of morphological evolution. Maximum likelihood estimates of the model parameters indicated that evolution of most characters tended to accelerate in the most recent taxa and was often independent from the phylogeny. Constraining the different characters to be independent from each other most often produced a less likely result than when the characters were free to evolve in a correlated fashion. Thus, the morphological characters that have traditionally been used to circumscribe different Amblystegium species lack the independence, diagnostic value for specific lineages, and stability that would be required for distinguishing different species.
通过划分环境和遗传诱导的形态变异，并使用比较方法关注形态进化，对传统上用于水生苔藓属钝叶藓属物种划分的形态特征的进化意义进行了测试。在受控条件下的培养实验表明，自然界中的大多数形态变异是由可塑性导致的。将来自多态性简单序列重复标记的遗传固定形态变异和遗传相似性信息整合到一个明确的形态进化模型中。模型参数的最大似然估计表明，大多数特征的进化在最近的分类群中趋于加速，并且通常与系统发育无关。与特征可以以相关方式自由进化时相比，将不同特征相互独立约束通常会产生可能性较小的结果。因此，传统上用于界定不同钝叶藓属物种的形态特征缺乏区分不同物种所需的独立性、对特定谱系的诊断价值和稳定性。
