Spotted Fish

Test Case(s): All tests described were preformed with no predators in order to conceptualize the propagation. The values used were: number of predators = 0 time to digest = 1.0 gestation period = 1.0 adult age = 5.0 old age = 150.0 hunting time scale = 0.5 mating time scale = 2 mutation factor = .9 Tests were made with the number of fish equal to 1, 2, 3, 4, 5, 6, and 100. Problem(s) annotations: Populations of size 2 and 5 result in no spotted fish babies in over 20 test runs that I preformed. Populations of size 3, 4, and 6 do cause for the fish to produce offspring. With no offspring created in populations of size 2 and 5, this model does not reflect biological systems and is invalid in this respect. Recommendations: There is likely a numerical error in the methods used by this project. Maybe there is not enough resolution in the variables being used.

The "spotted fish" model offers insight into a predator/prey relationship directly correlated to genetic diversity, i.e., natural selection/fitness. Thus evolution is clearly modeled as it occurs over time by tracking the diversity (spot size) and abundance of the prey population.

The model also easily allows for the alteration of an array of variables including: gestation period, mating time scale, and even the number of predator and prey. Therefore, hypotheses about the effects of altering these variables can be proposed and easily validated or refuted.

A criticism/point for improvement that I might propose in the case of this model is the parameter of the size/volume of the "virtual pond" is not alterable. The undefined volume of the pond hinders a true simulation of a predator/prey dynamic in that one cannot model in any respect in regards to space availability. It would be better to allow for at least a limited number of space considerations, i.e., 4 or 5 alternate pond sizes. Populations are too affected by availability of resources, such as spatial considerations, to negate these effects.

On the otherhand, the model's elimination of the availability of food as a parameter in the model is feasible. Assuming unlimited food in some environments is a "best case scenario" that is applicable.

The immediate use that I see for this tool would be an introduction to ecological problems, i.e., what happens when an invasive species is introduced into an environment where it has no natural predators, or what happens when a predatory species decreases in number, etc.

It could also be applied to a module on natural selection, however, the hereditability of this trait (spot size) would be a rather simple situation for a more advanced student population. The hereditability of traits aspect might be further built upon to make this module more suitable for an advanced student population. Perhaps the genotypes of parent populations could be included in the module? Some total for various phenotypes in the population pool could be displayed over time.