拓扑树间的通经拓扑距离

PATHWAY TOPOLOGICAL DISTANCES BETWEEN TOPOLOGICAL TREES

给出了一种新的系统树间的拓扑距离。使用NJ、MP、UPGMA等 3种方法对 13种动物的线粒体中 14个基因 (含组合的 )DNA序列数据进行系统树的构建。利用分割拓扑距离和本文给出的通经拓扑距离对这 14种系统树之间及其与真树进行比较。结果显示 ,NJ法对获得已知树的有效率最高 ,MP法次之 ,UPGMA法最低。这 14种DNA序列所构建的系统树与已知树的拓扑距离基本上是随其DNA序列长度增加而减小 ,但两者的相关系数并未达到显著水平。分割拓扑距离在总体上可反映树间的拓扑结构差异 ,但其测度精确度比通经拓扑距离要低。

A novel topological distance, called pathway topological distance was given in this paper to measure differences between phylogenetic trees. Fourteen mtDNA gene trees of 13 normal species were made using NJ, MP and UPGMA methods. The fourteen mtDNA gene trees were compared with the known phylogenetic tree using two criteria: partition topological distance and pathway topological distance. The result indicated that the NJ method has the highest efficiency of building phylogenetic tree among the three methods compared and the MP method has more efficiency than the UPGMA method. The topological distances between the reconstructed and the known phylogenetic trees roughly decline as the length of DNA sequence increases. However, the correlation coefficients between them were not significant at P=0.05 level. The partition topological distance can by and large measure the difference between phylogenetic trees, but has lower accuracy than the pathway topological distance.