This module simulates the contemporary evolution of a threespine stickleback population in a hypothetical lake, inspired by the findings from the Bell Lab (https://life.bio.sunysb.edu/ee/belllab/loberg.html)To run the simulations, you must first download and install NetLogo (version 5.3.1 or 6.0) on your computer. NetLogo is free and works on PC, Mac, and Linux. Go to the NetLogo download page.Download the Loberg Stickleback simlation module
The following processes serve as the underlying mechanisms of the module.
1. Food resource and population size
The stickleback fish need to obtain energy from the food. The changes in blue background represents the available food in the lake. The darker the patch is, the less food is available. Stickleback fish only obtain food from the less dark blue patches and every move costs some energy. If a fish runs out the energy and no food can be obtained from the current patch, it dies.The slider of "available-food" represents the food resource available for the stickleback population. 80~100 can be viewed as sufficient food, 50~70 as limited resource, 40 and below as lack of food recourse which can result in population crash.
2. Reproduction, inheritance and mutation
A simplified reproduction is used in the module. That is, when a fish cumulates a certain amount of energy, it produces a new fish. No mate is needed. 5 out of 100 offspring fish have more or less lateral plates compared to the parent fish.
The slider of "predation" determines the level of predation in the lake, varying from 0 to 3. When predation is greater than 0, dragonfly larvae will appear in the lake and prey on the stickleback. The complete-armored sticklebacks are more likely to be preyed in comparison with the low-armored fish.
CREDITS AND REFERENCES
This module is made by Dr. Lin Xiang at Weber State University. If you mention this module in a publication, we ask that you include the citations below.
Xiang, L. (2017). Loberg stickleback. Zoology Department, Weber State University, Ogden, UT.
The bell lab: Bridging the Gap Between Developmental Genetics and Paleontology (https://life.bio.sunysb.edu/ee/belllab/loberg.html)