Student work
Artificial life

Please note

The simulation needs a Java-Plugin (1.3.x) installed for your internet browser. If you do not already have one installed, the browser will prompt you to download the Plugin from “Sun”, who is the inventor of Java. Please download the JRE (=Java runtime environment) into a directory on your computer (e.g. “c:\temp”), execute the downloaded file for installation on your system (double-click on the file). Afterwards you will be able to reload the simulation page. Maybe you will have to restart your browser to succeed.

Run the simulation

Please click here.

Description of the simulation

Create a NetLogo-turtle that draws the first line (main branch).After she reached the end of her first step (starting-length), the turtle crates a new daugther-turtle that rotates to the right for a certain angle (sprout-angle).

The original (mother) turtle turns in the other direction (main-angle).

In the next step (2 turtles now), the length to be drawn is shortened, whereby main-shortening-factor sets the shortening of the line drawd by the mother-turtle, sprout-shortening-factor does the same for the daoughter’s line. This process is repeated several steps (4,8,16,... turtles) until they all rech thei maximum depth (number of sproutings).

The number of maximum sproutings is decreased after each sprouting step. Please note, that the daugther turtle becomes the mother turtle for the subbranch she created.


  • Tese the results of changing the angles, the depth and the shortening-factors. Interprete the results.



The presented NetLogo simulation was written by:
Thomas Schmickl (2003), Department for Zoology, Karl-Franzens-University Graz, Austria, Europe,,

Further readings

  • Malle H. (1995) Mathematik - ganz anders erleben. Verlag Harri Deutschm, Thun, Frankfurt am Main

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