Evolution of the primary’s mass distribution along the population during optimisation for the B5+B7 artificial system. Top row: value of the primary’s mass for a single individual in the population, with populations evolving as the generation number increases. The left and right panels show a zoom into the first 100 generations and the full evolution, respectively. Blue vertical lines in the right panel indicate the positions of the slices shown in the bottom panels. Bottom row: slices in the form of histograms for generations 0, 10, 50, 100, and 300 indicated with blue vertical lines in the top right panel.