  We have simulated demographic changes in the human population using the Penna
microscopic model, based on the simple Monte Carlo method. The results of
simulations have shown that during a few generations changes in the genetic
pool of a population are negligible, while improving the methods of
compensation of genetic defects or genetically determined proneness to many
disorders drastically affects the average life span of organisms. Age
distribution and mortality of the simulated populations correspond very well to
real demographic data available from different countries. Basing on the
comparison of structures of real human populations and the results of
simulations it is possible to predict changes in the age structure of
populations in the future.
