Fig. 4

Binding energy variability for tracked and new TFBSs. a Probability density functions (PDF) for the last generation distribution of the binding energy E for all TFBSs (red), new TFBSs (green), and sites tracked from the initial set of sites (blue). b Dynamics of the mean energy for the same three sets of sites as in (a), with the same colour code. For all and new sites, the energy was averaged across the 20 best individuals, and for the tracked sites, across the sites of a randomly chosen sequence from the 20 best fit individuals. c Temporal distributions of the coefficient of variation (CV =SD/mean) of E for the same three sets of sites as in (a) and (b), with the same colour code. The CV values correspond to the E variation within the population in a given generation, and the plotted distributions comprise CV values for all generations. The first 100 generations were not taken into account in the distributions due to a small number of new sites in that period (see Fig. 2 b). d Dynamics of the low energy sites number to the high energy sites number ratio for the tracked TFBSs. The sites were classified to the low and high energy sets using E=4 as the threshold. The arrows mark two stochastic bursts of the amount of low energy sites during the evolution