A Test of Mutational Constancy Based on the Comparison of Forward and Reverse Rates of Nucleotide Substitution

Under the assumption that mutation rates are constant between two classes of genomic sequences, one can calculate the strength of fixational bias that underlies the variability in forward and reverse substitution rates. When fixation biases thus inferred are too strong, the mutation rates must vary along with the substitution rates.

To compute the strength of selection under the hypothesis of mutational constancy, please input F and R - the ratios of forward and reverse evolutionary rates between two sequence classes:

F= (a number greater than 1)

R= (a number between 0 and 1)

To compute the minimum contribution of mutational variation to the variation in substitution rates, enter S - the upper bound on the selection coefficients Ns1 and Ns2:

S= (a number greater than 0)

This web application was designed and implemented by Peter Arndt, Misha Lipatov and Dmitri Petrov in 2004. Email Misha Lipatov (lipatov at stanford dot edu) with questions about its usage and interpretation of the results.

If you use this tool in your work, please cite the recent publication which describes its methodological underpinnings:

Mikhail Lipatov, Peter F. Arndt, Terence Hwa, Dmitri A. Petrov, A Novel Method Distinguishes Between Mutation Rates and Fixation Biases in Patterns of Single-Nucleotide Substitution, Journal of Molecular Evolution, Volume 62, Issue 2, Feb 2006, Pages 168 - 175, DOI 10.1007/s00239-005-0207-z, URL http://dx.doi.org/10.1007/s00239-005-0207-z.
Link to the article at the website of Journal of Molecular Evolution.