Figure 2. Stochastic model of HSC cell fate decisions.

1 – initial cells (a total of 300); 2-5 – initial cell parameters; 6-15 – cell fate decisions during model cycle updated in “weekly” increments throughout the simulated human 85 year lifespan; 16 – cell leaves the pool. Timing of cells division (8), net fitness change per division (12), and fitness-based competition for niche space (14) are defined in stochastic trials based on distributions of average division timing, mutation DFE, and fitness-dependent stochastic competition scheme, respectively.