Have fun with breeding goldfish !!!!
This model helps students observing the phenomenon of variation. Students can breed a pair of goldfish. They will see some offspring's color always slightly different from their parents. This model also demonstrates artificial selection. Students can breed the fish to test how selection pressure affects fish color evolution over time.
In this model, each pair of fish reproduce 30 offspring fish whose colors are determined by their parent color number, with some variation-either lighter or darker.
1. First, push "start a fish tank" to begin. The number attached to each fish indicate its color. e.g., 21-29 are different shades of orange, 11-19 are different shades of red. The fish color may be as dark as black when the number gets close to an integer multiple of 10, such as 10,20,30.
2. Press "Go! Fish Go!" to let fish swim around. You may choose fish to breed at this time. You only select one fish with your desired color, and then the simulation will pair a fish with the same color to produce offspring fish. In this model, each pair of fish reproduce 30 offspring fish whose colors are determined by their parent color with some variation-either lighter or darker.
3. You may press "stop! Let me pick fish" to stop fish swimming so you can pick fish easily.
The NetLogo model was developed by Dr. Lin Xiang at Weber State University. If you mention this model in a publication, we ask that you include the citations below.
Xiang, L. (2017). Artificial Selection-Fish Tank. Zoology Department, Weber State University, Ogden, UT.
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