The paper that was supposed to be online on the 7th is finally up. A highly unexpected strong correlation between fixation probability of nonsynonymous mutations and mutation rate:
Under prevailing theories, the nonsynonymous-to-synonymous substitution ratio (i.e. Ka/Ks), which measures the fixation probability of nonsynonymous mutations, is correlated with the strength of selection. In this article, we report that Ka/Ks is also strongly correlated with the mutation rate as measured by Ks, and that this correlation appears to have a similar magnitude as the correlation between Ka/Ks and selective strength. This finding cannot be reconciled with current theories. It suggests that we should re-evaluate the current paradigms of coding-sequence evolution, and that the wide use of Ka/Ks as a measure of selective strength needs reassessment.
FYI to be simple about it nonsynonymous mutations change the amino acid coded for and synonymous ones do not. Fixation is when the frequency of an allele in the population ~100%, that is, it has become a monomorphic locus (this tends to be common for genetically coded traits which show no intraspecies variation, at least heritable variation).
Posted by razib at 07:25 PM