作者：张 驰
摘要：贝叶斯支端定年法是近些年开发的推断类群分异时间和演化速率的方法。它克服了传统分步计算的缺陷，但涉及到的统计学知识也更多。本文从贝叶斯统计计算的角度分层剖析了支端定年法的原理和计算过程，按照分异时间的先验分布、演化速率的先验分布、特征状态变化的模型和马氏链蒙特卡罗算法几个部分，叙述并讨论了定年计算中的主要模型和算法。旨在一定程度上为古生物学家分析实际数据提供参考。
关键词：贝叶斯支端定年法，石化生灭过程，宽松钟，Mk模型，MrBayes
Using Bayesian tip-dating method to estimate divergence times and evolutionary rates
ZHANG Chi
Abstract Bayesian tip dating is a recently developed method to estimate divergence times and evolutionary rates. It overcomes several drawbacks in traditional stepwise approach. However, it also requires more knowledge about statistics. This paper hierarchically explains the theory and computation in the Bayesian tip-dating approach, and divides the whole process into prior for the divergence times, prior for the evolutionary rates, model for the character changes and Markov chain Monte Carlo algorithm, which are key components in this method. The aim is to provide a general guidance for paleontologists in empirical data analyses.
Key words Bayesian tip dating, fossilized birth-death process, relaxed clock, Mk model, MrBayes
