{retorte petridish: microorganism simulator introduction}
Introduction, Graph, Current situation, Strain top ten, Create your own strain!, Frequently asked questions
Retorte Petridish is an agent-based simulation of a petridish holding a certain number of microorganisms (mostly bacteria) which on their part belong to a bacteria strain.
Strains can have different properties and the single agent (i.e. bacterium) of a strain behaves with his simple rules according to these properties.
In this simulation we use these properties to describe a bacterium strain:
- Maximum Speed
- Strength/Energy level
- Range of Perception
- A food index describing the kind of food the strain is able to eat
- A feeding diversity rate defining the range of food types the strain can eat
- Aggressivity/Likeliness of attacking a neighbour and/or getting energy from other bacteria instead of protein clusters
- Cell division threshold
The single agent itself has only a very limited behavioral repertoire. The simulation gains its power mainly through the very big number of single agents who act in (virtual) parallel. Every one of them does the following things independently:
- Maximize own energy level
- Look for nearest food item (within perception range and food index diversity) and try to catch it
- Possibly attack enemy bacteria who pursue the same food item or accidentally come across the neighbourhood
- Purposely attack enemy bacteria to gain energy
- Keep alive the strain
- Reproduce if energy level is high enough
- Attack bacteria of other strains (if aggressivity high enough)
The simulation is discrete and updates every 15 minutes. Although it is a closed system, the energy a bacterium uses for movement can't be preserved (it is used to heat the petridish) which is why there are food items added every hour until the energy level in the system is at the original level. Besides that little flaw the energy level remains constant.
Every new strain is inserted exactly once. A certain number (30 at the moment) of bacteria of that strain are inserted at random positions in the petridish.
If the single agent eventually divides, there is a small probability that a mutation occurs; in that case one or more of the agents properties are slightly changed. If the discrepancy between the agents properties and those of the respective strain grow too large, the mutant agent establishes a new version of the strain of which he is the first exponent.