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Sex and the Single Guppy

Intro | Discovery | Hypotheses | Simulation 1 | Analysis 1 | Simulation 2 | Analysis 2 | Conclusion | Gallery

Analysis of Simulation Two:

Your settings:

Initial population: Even mix
Predators: 30 rivulus, 30 acara, 30 cichlids

After maintaining your simulation pool for only one year, you find a significant decline in the number of moderately colored guppies. The brightest males and drabbest males are still faring pretty well under the extreme predation pressure, but all others are quickly weeded out of the population.

Number of guppies: 171
Number of generations: 4
Number of weeks: 57
Male color types:
    Brightest: 15%
    Bright: 9%
    Drab: 26%
    Drabbest: 50%

guppy simulation after 1 years

In four years (or about seven guppy generations), the brightest males are beginning to bear the brunt of the predation pressure, while the drabbest guppies in the population dominate. After six years, the drabbest guppies make up 90 percent of the population, and it's clear that the brightest guppies' days are numbered. This trend is similar to the one Endler observed in the lower sections of Trinidad streams, as well as in the experimental pools he stocked with many predators.

Number of guppies: 100
Number of generations: 7
Number of weeks: 203
Male color types:
    Brightest: 0%
    Bright: 0%
    Drab: 4%
    Drabbest: 96%

guppy simulation after 4 years

-> What conclusions can we draw from our two simulations?

Intro | Discovery | Hypotheses | Simulation 1 | Analysis 1 | Simulation 2 | Analysis 2 | Conclusion | Gallery

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