基于DNA序列的系统进化树构建

Construction of phylogenetic tree based on DNA sequences

【目的】利用生物DNA序列构建系统进化树,以分析生物的进化过程。【方法】利用最大似然估计原理,给出了构建系统发生树的模型和算法。分别建立了确定父节点的ML模型、确定进化时间的ML模型以及保守概率与相似度关系模型;并通过递推,逐步恢复生物进化的原过程。【结果】给定一系列生物的DNA序列,通过本算法可以建立这些生物的系统进化树,以及生物各自父辈的DNA序列和进化时间。【结论】由本研究构建算法得到的生物进化关系合理、算法复杂度低,可以用于大规模生物群体的系统进化树构建。

【Objective】 The study constructed phylogenetic tree based on DNA sequence to analyze the evolutionary process of organism.【Method】 A model and an algorithm were provided for constructing phylogenetic tree based on the principle of maximum likelihood estimate.Firstly,the ML model was given to determine father node,evolutionary time and the relationship between conserved probability and similarity.Then the process of organism evolution was recovered.【Result】 Given a set of DNA sequences,phylogenetic tree can be constructed by our algorithm.Also,the father sequences and the evolutionary time are obtained from the evolutionary tree.【Conclusion】 Phylogenetic trees obtained from our algorithm are rational.Furthermore,the algorithm is simple,and can be used to construct phylogenetic tree in large scale DNA sequences.