Chemostat Simulation 4

In this simulation, nutrients (shown in green) flow in from the right hand side. The initial population of grazing animals is 10. The population rises to about 30.

In this model, however, the offspring of each grazer has a 50% chance of being either a slower or faster reproducer. The result is that faster reproducers (yellow and white ones) gradually predominate over the slow reproducers (blue and black). At the same time, the carrying capacity - and mean population - falls. The process usually stops when the population can only just span the width of the stream.