Simulation results on clonal conversion during aging. Given is the clone distribution (characterized by clone specific d / f_α(Ñ) values) within a model system starting from the initial situation (A) at different time points: 6 months (B), 12 months (C), and 24 months (C). The system had been initiated with 1000 clonally distinguishable HSCs. Each dot in the graphs (A-D) represents one particular clone. The corresponding frequency tables show the distributions of engraftment patterns obtained from 10 000 simulations, each initiated by the transplantation of 1 randomly chosen cell from the given stem cell pool in competition with 4 host cells.