Visual representation of evolution and resulting clonal heterogeneity in a tumor that grows to 3.5 billion cells over the course of three driver mutations that occur within four years. A. Parameters of the simulation. The grey clone originates with the first driver mutation that sets f = 0.60, and t = 2 weeks. 100 weeks later the purple clone originates due to a driver that decreases t to 1 week (f does not change). A further 60 weeks later, the orange clone arises by a driver that sets f to 0.75. B. Five time points of this tumor’s evolution. Area sizes are proportional to the number of cells in each clone. After four years (208 weeks), each clone is approximately the same size, 1 billion cells each, comprising a solid tumor of about 3.5 cubic centimeters.