On the evolution of codon volatility.
Volatility of a codon is defined as the probability that a random point mutation in the codon generates a nonsynonymous change. It has been proposed that higher-than-expected mean codon volatility of a gene indicates that positive selection for nonsynonymous changes has acted on the gene in the recent past. I show that strong frequency-dependent selection (minority advantage) in large populations can increase codon volatility slightly, whereas directional positive selection has no effect on volatility. Factors unrelated to positive selection, such as expression-related or GC-content-related codon usage bias, also affect volatility. These and other considerations suggest that codon volatility has only limited utility for detecting positive selection at the DNA sequence level.
Zhang
Jianzhi
J
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan 48109, USA. jianzhi@umich.edu
D000818:Animals; D001482:Base Composition; D005075:Biological Evolution; D003062:Codon / Q000235:genetics*; D020862:GC Rich Sequence; D005796:Genes / Q000235:genetics*; D016678:Genome; D006801:Humans; D009154:Mutation / Q000235:genetics*; D012641:Selection, Genetic
D003062:Codon