Ap Bio Wisconsin Fast Plants

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This experiment, which was used to explore the Theory of Evolution created by Charles Darwin. The use of natural selection was apparent in the artificial modification of an organism's traits which aided in this investigation. Through this experiment the Wisconsin Fast Plant was used. It is a fast-growing organism developed to improve the resistance to disease in cruciferous plants. This plant aids scientist in the exploration of environmental effects on population due to the speed to which is matures and reproduces. Artificial selection was stimulated by the selection against plants with few hairs(trichomes). Trichomes create a wider variation which means it is polygenic. The plants that had only a few trichomes were exterminated and the rest were pollinated to create an F2 generation. This was done in an attempt to increase the number of plants with many hairs in the next generation. It turned out to be a successful use of natural selection due to the decreased amount of bald plants from the F1 generation to the F2 generation.

Charles Darwin a researcher who traveled to South America studied a wide range of plants and animals. Through his extensive research he came up with the idea of artificial selection. Artificial selection is the process of humans modifying species to get the desired traits, for example; dog breeders breed two different dog species until they get all the desired traits in the offspring. The breeding of domesticated animals is where Darwin derived his theory of artificial selection. Darwin believed that natural selection should modify species of a longer period of time. In order to test this claim, Wisconsin Fast plants were grown. Once matured, the plant would be artificially selected based on the number of trichomes it contained. Professor Emeritus Paul H. Williams developed these plants in the Department of Plant Pathology at the University of Madison in Wisconsin. The reason for creating these plants was to use for research on improving disease resistance of cruciferous plants. He used seven types of cruciferous plants to create this breed; which included Brassica rapa. This new plant had many benefits such as allowing scientist to test environmental effects on an entire population. There are many variations of the Wisconsin Fast Plant including; hairy, hairless, purple-stemmed, and solid with varied leaves. The interest in this experiment is the fact that it recreates Darwin's theory of Natural Selection by using the hairless plants as the test subject of being “selected against.” If a plant had less than 10 trichomes from the stem to the cotyledon then it would be exterminated before pollination. This was done to modify the genes in the seed of the F2 generation. The purpose of this experiment was to use artificial selection to test Darwin's theory in a timely manner as apposed to watching natural selection of a long period of time. This information is where the hypothesis was derived from; If Hairy plants and hairless(which contained different variations of quantity of hair) plants are cross-pollinated, and the less hairier offspring of the cross-pollination was selected against, then the F2 generation will contain hairier plants than the previous generations, as that being the desired trait.

Trichome number in the first generation (F1)
0 | 135 |
1-5 | 18 |
6-10 | 9 |
11-15 | 8 |
16-20 | 4 |
21-25 | 6 |
26-30 | 2 |
31-35 | 3 |
36-40 | 0 |
41-45 | 3 |
Number of Trichomes | Number of plants |

The table helps to conclude that the F1 generation that had ten or less trichromes made up 86% of the population were exterminated. This only left 14% with more than ten trichomes to be cross-pollinated and able to produce offspring. Trichome number for second generation (F2)

0 | 13 |
1-5 | 1 |
6-10 | 9 |
11-15 | 4...
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