SGA remains approximately constant over time in most individuals.

Black lines indicate 10 individuals with apparent evolutionary stasis and red lines indicate 3 individuals with apparent increase in SGA over time. (Panel A) Mean number of SGA lesions. Solid lines connect the means at each time point for all individuals (a–m), where the symbols a–m are plotted at the end of the lines. (Panel B) Mean amount of genome affected by SGA.