Computer Simulations for Biological Ageing and Sexual Reproduction
  The sexual version of the Penna model of biological ageing, simulated since 1996, is compared here with alternative forms of reproduction as well as with models not involving ageing. In particular we want to check how sexual forms of life could have evolved and won over earlier asexual forms hundreds of million years ago. This computer model is based on the mutation-accumulation theory of ageing, using bits-strings to represent the genome. Its population dynamics is studied by Monte Carlo methods. 
D. Stauffer, P.M.C. de Oliveira, S. Moss de Oliveira, T.J.P. Penna and   J.S. Sa' Martins