Evolution 2 - Selection and mutation

The simulation below illustrates a simple evolutionary process that involves reproduction, selection and mutation. In the beginning a single “cell” exists. When you start the simulation, this cell reproduces stochastically, generating offspring of the same type. The reproduction is governed by the fitness. Every now and then the cell can generate a mutant (different color) with a different fitness than the parent. The fitness of the mutant is chosen randomly once and will remain fixed for the mutant. Mutants can also give rise to new mutants. The mutation rate is fixed for all types. When a given capacity is reached cells also die, keeping the population size fixed.

One can observe that quickly mutants take over the population that have a high fitness. When this happens new mutants that emerge tend to have a smaller fitness and go extinct quickly (white dots on axis on bottom). The average fitness of the population is shown by the red moving dot on the axis.