Figure 4.

Exponential relationship between E2F replacement turnover rate and sequence divergence distance. The x-axis is the evolution divergence measured by the number of substitutions per site, and the y-axis is the RTR of an E2F site in a descendent sequence. The points are values observed from simulation, and lines are values predicted by the exponential model given in equation 2. (a) E2F replacement turnover rates observed in an evolution simulation starting from simulated ancestral promoter sequences, where λ is 0.0832 and 0.0724 for fitting the mean and median, respectively. (b) E2F replacement turnover rates observed in an evolution simulation starting from real human promoter sequences, where λ is 0.0833 and 0.0755 for fitting the mean and median, respectively.