Molecular Biology and Evolution 18:1157-1160 (2001)
© 2001 Society for Molecular Biology and Evolution
Statistics of Divergence Times
Max-Planck-Institut für Chemische Ökologie, Jena, Germany
Given the number of nucleotide substitutions between two species (K) and the substitution rate
, the expectation of the corresponding divergence time is usually calculated as K/(2
). This is strictly true only if
is regarded as a constant because the ratio of two random variables, such as K/(2
), has distributional properties different from those of the distribution of K. Therefore, both the mean and any confidence interval for divergence times are unknown in this situation. We model the distribution of K and
using the Gamma distribution and calculate the mean and 95% confidence interval for the corresponding divergence time. These calculations are compared with results obtained by bootstrapping sequence data from the model plant Arabidopsis thaliana and its relatives. We show that for nonoverlapping pairs of phylogenetic distances, our method approaches the bootstrap results very closely. In contrast, regarding the mutation rate as a constant leads to strong underestimation of the confidence interval. An implementation of our method of computing divergence times is accessible through a web interface at http://www.soft.ice.mpg.de/cite.
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
A. Willyard, J. Syring, D. S. Gernandt, A. Liston, and R. Cronn Fossil Calibration of Molecular Divergence Infers a Moderate Mutation Rate and Recent Radiations for Pinus Mol. Biol. Evol., January 1, 2007; 24(1): 90 - 101. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. M. Laten, E. R. Havecker, L. M. Farmer, and D. F. Voytas SIRE1, an Endogenous Retrovirus Family from Glycine max, Is Highly Homogeneous and Evolutionarily Young Mol. Biol. Evol., August 1, 2003; 20(8): 1222 - 1230. [Abstract] [Full Text] [PDF] |
||||
