Wednesday, October 27, 2010

Guppy Simulation

1. If being flashy and colorful attracts predators, why do you think guppies are so colorful?
Guppies are so colorful because females are more attracted to the bolder physical appearance. These genes are then passed down, causing a higher population of brightly colored males. Also, the predators that have been able to spot the bolder males helps manage the guppy population in the wild.  

2. After viewing the guppy gallery, pick the fish you find most interesting. What is the fish’s scientific name, origin and average size? Describe the coloration of the fish you chose.
Common name: Guppy or millions fish
Scientific Name:Poecilia reticulata
Gender: male
Size: 1.4 inches
Origin: Brazil
Coloration: More silver in color with yellow spots along the side, as well as black markings on their underside and an orange, white, and black fin.

3. After viewing the predator gallery, pick the fish you find most interesting. What is the fish’s common name, scientific name, and origin?
Common name: Fat Sleeper
Scientific Name: Dormitator maculatus
Origin: Southern North America, Bahamas, and LAtin America.

4. View the guppy’s habitats, what habitat conditions would affect the predator populations?
Dams with what looks like a waterfall provides a good, sustainable habitat for guppies in Trinidad. Populations of guppies above the dam would suffer little to none predator restrictions.

Endler’s Discovery and Variations of Guppy’s in Pools

5. Who is John Endler? What did he study and where did he study it?
John Endler was a scientist in the 1970s who studied wild guppies' patterns and physical qualities such as size and especially color. This study took place in Trinidad.

6. For each of the three stream areas, describe the guppy coloration:

Pool 1:There are 75 guppies in pool 1. The males are brightly multi-colored with large spots.

Pool 2: There are 83 guppies. The males have medium coloration on their bodies and tails, while also displaying medium-sized spots.

Pool 3: There are 110 guppies. The males are drab in color and have tiny dots that are more concentrated near their tail.

7. Develop your own hypothesis about guppy coloration. The hypothesis should answer the questions: Why do guppies in different areas of the stream have difference in coloration? (You can choose from the list on the simulation, or make up your own)
Hypothesis: In some areas of the stream, there is little predation pressure, so the males will pass on the bright color gene because they attract the females. In other areas with a higher population of predators, males pass on the drab gene because they need to be "fit" to survive with the predators so nearby.

Guppy Simulation

% of Brightest Guppies
(10 generations)

% of Bright Guppies
(10 generations) % of Drab Guppies
(10 generations) % of DrabbestGuppies
(10 generations)

Trial 1

Guppy: Even Mix
Predators: 30 Rivulus
# of weeks: 248
% of guppy coloration: 31% brightest male, 55% bright male, 8% drab male, 6% drabbest male
Analysis: With the ratio of male guppies to predators, there was an excess of successful passing on of genes, so more than half the quantity of male guppies were bright in color.

Trial 2

Guppy: Even Mix
Predators: 30 Rivulus, 30 Acara
# of weeks: 234
% of guppy coloration: 60% brightest male, 2% bright male, 33% drab male, 5% drabbest male
Analysis: Though the stream was equally stocked, the brightest and drab males were the most plentiful. This could be a result of an equal amount of predators, as well as an even amount of guppies.

Trial 3

Guppy: Even Mix
Predators: 30 Rivulus, 30 Acara, 30 Cichlid
# of weeks: 382
% of guppy coloration: 0% brightest male, 0% bright male, 2% drab male, 98% drabbest male
Analysis: Drab males became more plentiful because there were more predators to hide from, therefore, the genes that got passed on were the drab coloration. This provided future generations with more "fit" genes.

Trial 4

Guppy: Mostly Bright
Predators: 30 Rivulus
# of weeks: 275
% of guppy coloration: 80% brightest males, 18% bright males, 2% drab males, 0% drabbest males
Analysis: The biased start with a higher population of brightly colored guppies had a consequence of having a higher amount of brightly colored males at the finale.

Trial 5

Guppy: Mostly Drab
Predators: 30 Rivulus, 30 Acara, 30 Cichlid
# of weeks: 248
% of guppy coloration: 0% brightest males, 3% bright males, 19% drab males, 79% drabbest males
Analysis: According to the results in the simulation, there was a significant drop from each category in the percentage of guppy coloration. For example, there is a 60% drop from drabbest to drab guppies.


8. Describe how predators influence guppy coloration.
When there is a large abundance of predators, there will be a higher population of drab colored males. This happens because the drab guppies attract less predators and are easier to camouflage themselves in its surroundings. When there are less predators, the number of bright colored males are more plentiful because the males' main concern is to attract a female. Also, there is less of a need to hide from predators in this case.

9. Was your hypothesis correct, use your data to justify your answer.
My hypothesis was correct because, according to the simulation results, the tests in which there was a significant increase in predators showed an increase in drab males, and vice versa. The tests that commenced with a more biased quantity of bright or drab males also followed protocol by showing that bright males attract females in little predator situations, and predators in high predator situations. The end results are inverse for the opposite operations.

10. What does it mean that “male guppies live in a crossfire between their enemies and their would be mates”?
The "male guppies live in a crossfire between their enemies and their would be mates” means that they are torn between passing on the gene that attracts females while also putting a spotlight on themselves for predators, and not being able to attract females, but then again, also having the advantage of not being spotted so easily by predators.

11. Why do you think guppies in different areas of the stream have different coloration?
Guppies in differ ent areas of the stream have different coloration, because the introduction to the simulation illustrated that not every section of the stream is completely accessible to all predators, therefore limiting the presence of raptorial animals. This would allow the guppies to express their bright colors to attract females without being detected by predators. In areas where there are high waters, for example, predators have more access to the site, hence the dull coloration of the guppies.

12. What would happen to mostly drab guppies that were placed in a stream with very few predators?
The drab guppies would die out because they do not have the natural ability to attract female guppies. Their drab coloring is only useful when trying to hide from predators.

13. What would happen to brightly colored guppies that were placed in a stream with many predators?
The brightly colored guppies would die out because they would't be able to pass on their gene, due to natural selection. They are unable to conceal themselves in the water due to their vivid hues and patterns.

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