Figure 1

A first order exponential describes the fraction of two fold sites that are identical (f₂) versus the number of changes per site, which can be expressed as process is the consequence Schematic showing the fraction of residues at two fold redundant sites conserved after a time t, with an end point of 0.53. Note that in this plot, if we assume that the rate constant for transition is time-invariant, the x axis corresponds to time.