The distribution of the number of followers (in-degree) in the initial and evolved networks.

<p>(a) The solid line is the initial Poisson distribution with a mean of 5. The markers (the circle and +) denote the in-degree distributions of the evolved network with rewiring thresholds <i>θ</i> = 0.5 and 0.6, respectively, obtained over 500 independent runs of our simulation. The in-degree distributions in the evolved networks are significantly different from the initial condition, showing much higher heterogeneity in in-degrees. (b) The same as (a) except that the vertical axis is logarithmically scaled. We can observe the approximately exponential tails in the evolved networks.