Lycophytes, Bryophytes, and Charophytes: Testing Morphology and Molecule-Based Hypotheses

小行星9408057 来自细胞核和细胞器DNA的分子数据，结合用于系统发育分析的数值算法，彻底改变了植物进化的研究。 路易斯安那州州立大学的拉塞尔·查普曼博士是将这些分子和分类学方法应用于分析绿色藻类和所谓的低地植物如苔藓和石松的领导者。 他主要关注核核糖体基因序列，证明了苔藓类（苔藓、地钱和金鱼藻）虽然可能是陆地植物最早的分化谱系，但它们本身并不是一个单一的进化单位，而是一系列陆地“实验”。“正在收集更多的DNA数据，以测试各种苔藓类群的系统发育亲和力，特别是评估目前将苔藓分类为17个不同亚目的实用性。 随着样品的获得，分子分析也将应用于原始维管植物的相关群体，石松（石松和亲戚）。 与其他实验室正在进行的形态学和超微结构研究相关联，查普曼博士进行的核核糖体DNA分子系统发育分析为植物适应陆地生活的变化方向和克里思提供了见解。

9408057 Chapman Molecular data from nuclear and organellar DNA, in conjunction with numerical algorithms for phylogenetic analysis, have revolutionized the study of plant evolution. Dr. Russell Chapman of Louisiana State University has been a leader in the application of these molecular and taxometric methodologies to the analysis of green algae and of so-called lower land plants such as mosses and club-mosses. Focussing primarily on nuclear ribosomal gene sequences, he has shown that the bryophytes (mosses, liverworts, and hornworts), while likely to be the earliest diverging lineages of land plants, are themselves not a single evolutionary unit but a series of terrestrial "experiments." Additional DNA data are being collected to test the phylogenetic affinities of various bryophyte groups, and in particular to assess the utility of the current classification of mosses into 17 distinct suborders. As samples become available, molecular analyses will also be applied to related groups of primitive vascular plants, the lycophytes (club mosses and relatives). In association with morphological and ultrastructural studies underway in other laboratories, the molecular phylogenetic analyses of nuclear ribosomal DNA conducted by Dr. Chapman are providing insight to the direction and tempo of change in plants as they adapted to life on land.