Gu X
Institute of Molecular Evolutionary Genetics, Pennsylvania State University, University Park 16802, USA.
Mol Biol Evol. 1997 Aug;14(8):861-6. doi: 10.1093/oxfordjournals.molbev.a025827.
In this paper, a simple distance measure was used to estimate the age (T) of the common ancestor of eukaryotes and prokaryotes which takes the rate variation among sites and the pattern of amino acid substitutions into account. Our new estimate of T based on Doolittle et al.'s data is about 2.5 billion years ago (Ga), with 95% confidence interval from 2.1 to 2.9 Ga. This result indicates (1) that Doolittle et al.'s estimate (approximately 2.0 Ga) seems too recent, and (2) that the traditional view about the divergence time between eukaryotes and prokaryotes (T0 = 3.5 Ga) can be rejected at the 0.1% significance level.
在本文中，我们使用了一种简单的距离度量方法来估计真核生物和原核生物共同祖先的年龄（T），该方法考虑了位点间的速率变化以及氨基酸替换模式。基于杜利特尔等人的数据，我们对T的新估计约为25亿年前（Ga），95%置信区间为21亿年至29亿年。这一结果表明：（1）杜利特尔等人的估计（约20亿年）似乎过于近期；（2）关于真核生物和原核生物分化时间的传统观点（T0 = 35亿年）在0.1%的显著性水平上可以被拒绝。
