Simulated Evolution

by Michael Palmiter, Ph.D.

This program simulates the evolution of hunting behavior in a predator/prey situation. The computer screen represents a microscopic patch of primeval lake bottom. Protozoa, or "bugs," move about the screen devouring bacteria, which are their source of energy. Each bug's behavior is genetically determined by a "chromosome" consisting of six "gene numbers," which control the bug's cruising pattern.

A bug reproduces when:

1. It has accumulated sufficient energy
2. It is old enough to be considered "mature". Reproduction is not exact: the two offspring differ slightly from the parent bug (and from each other). This is effected, at birth, by a random mutation of one gene number per offspring.

All the essential elements of the evolution (variation & natural selection) are present in the simulation. There is not one line of code in the program that tells the bugs how to solve their problems. They truly live, die, and evolve according to their own genetic merits (and the chance circumstances of existence in their environment). Four different species of bug have been seen to evolve on the screen (these are described in the User's Manual in the chapter called "Natural History of the Bugs." Also, various "genetic disorders" are occasionally seen among the bugs.

Legend:

1. Protozoans ("bugs") cruising the screen, hunting bacteria.
2. Small, purple bacteria; source of food and energy for the bugs.
3. The "Garden of Eden"; a dense patch of bacteria (two-species option only).
4. Bright blue border; an impassible barrier to the bugs.
5. Population; the number of bugs on the screen. When the "B" option is active, this is replaced by the age and energy of the "blue bug."
6. Percentage of each type of maneuver occurring on the screen (see abbreviations listed below). When the "B" option is active, these become the percentage of each type of maneuver executed by the "blue bug."
7. When the "G" option is active, the 6 numbers on the left become the population averages of the gene numbers.
8. When recording a run: frame number of the most recently recorded frame. When replaying a run: frame number of the frame currently being played.

Abbreviations appearing on the left side of the screen:

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Evolution in Primordial Soup

by Garvin Boyle

This program is a new Windows elaboration of Simulated Evolution above with greatly expanded features. Evolution occurs on your computer.

Scenarios - PSoup is able to demonstrate a variety of different environments (or configurations) in which evolutionary processes operate. Each instance of a bowl of PSoup, whatever the configuration, is called a scenario. PSoup comes with a number of canned scenarios, but also offers the ability for the user to develop and save his/her own scenarios. The ‘tinker’ commands allow the user to modify the configuration of the bowl of PSoup, including the rules of chemistry used behind the scenes, as well as the genetic structure of each of the denizens of the bowl. In Level 1, the tinker commands have limited capabilities. By the time a student achieves Level 6, the tinker commands are fully enabled.

Email LSA for the complete PSoup primer.

Download Demo (3.7 MB)
Execute file and follow on-screen prompts.

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