Relaxing the Molecular Clock to Different Degrees for Different Substitution Types.

ABSTRACT: Rates of molecular evolution can vary over time. Diverse statistical techniques for divergence time estimation have been developed to accommodate this variation. These typically require that all sequence (or codon) positions at a locus change independently of one another. They also generally assume that the rates of different types of nucleotide substitutions vary across a phylogeny in the same way. This permits divergence time estimation procedures to employ an instantaneous rate matrix with relative rates that do not differ among branches. However, previous studies have suggested that some substitution types (e.g., CpG to TpG changes in mammals) are more clock-like than others. As has been previously noted, this is biologically plausible given the mutational mechanism of CpG to TpG chang

SUBMITTER: Lee HJ 

PROVIDER: S-EPMC4833082 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature