Simulation of aging with an extended Penna model

We employed the Penna model for computer simulation of population evolution when it is controlled by (a) hunting out some of the population as well as (b) to find out the role of fluctuations in threshold T for the maximum number of bad mutations on population growth dynamics. Extinction of population may be caused by too many mutations inherited by offspring. Overhunting acts in the same way and may also result in vanishing of the whole population. When both factors are present, we get a critical line that defines a sharp transition between existence and non-existence of the population. A distribution of T around its average value with some width Δ may reflect some individual resistance to illnesses, or some non-inherited somatic mutations. Structural changes in the final population as a result of overhunting or threshold T fluctuations are observed.