Estimated selection coefficients for transition mutations along the <i>pol</i> gene.

<p>Point estimates for the selection coefficients for each transition mutation along the <i>pol</i> gene. Synonymous mutations are shown in yellow, non-synonymous mutations are shown in light red (C→T or G→A mutations) and purple (T→C or A→G mutations), nonsense mutations are shown in black. This plot illustrates that estimated selection coefficients do not appear to be affected by location in the gene. Note that these histograms include mutations that create CpG sites and those that don’t, which means that the effect that G→A and C→T mutations are more costly than non-CpG forming A→G mutations is not visible in this figure.