Bak-Sneppen Evolutionary Model

• Download Bak-Sneppen



• This version of the Bak-Sneppen model was programmed by Steve Baedke, with documentation by Lynn S. Fichter, both of the Dept. of Geology and Environmental Science, James Madison University.



• This program is copyrighted, but may be downloaded and used by anyone for personal or education purposes as long as the source is acknowledged. Commercial distribution of the program is prohibited.



• Program is based on a description in: Bak, Per and Kim Sneppen, 1993, Punctuated Equilibrium and Criticality in a Simple Model of Evolution: Physical Review Letters, Vol. 71, No. 24, p 4083-4086

1. "We have studied many different versions of this model, and in all cases we found self-organized criticality. The behavior is robust - as it must be to represent real evolution since our models will certainly differ from the real thing when it comes to details."



2. "But, the most interesting feature of the model is its extreme simplicity and robustness; it has no subtle structure. We believe that only a few conditions need to be satisfied for the model to work. The picture which seems to emerge from our model is that while evolution does take ecology to the critical point by its self-organizing dynamics, the fitness of that point is not particularly high."



3. "In the critical state the species are connected at all scales, as illustrated by the power law distribution of avalanches. Since all species belonging to a single avalanche become extinct together, they might as well be viewed as a single organism. We thus have a hierarchical organization of organisms, up to and including the total ecology; thus one may speculate that the whole system in the self-organizing critical state acts as one interconnected organism, as suggested by Lovelock's Gaia hypothesis."