Lesson 3 Essay

635 WordsFeb 5, 20163 Pages
Lesson 3 Essay Questions: 1- Compare and contrast directional selection and disruptive selection, and provide an example of each. Directional selection occurs when one extreme of a trait is favored and the distribution curve shifts in that direction. An example of this is the human struggle with malaria. The mosquito Anopheles transmits the disease. A new drug for the disease and a insecticide for the mosquito was created. But over the years they became resistant to it and multiplied, shifting the distribution curve toward the resistant type of parasite. Disruptive selection is where any two extremes of a trait are favored over any intermediate phenotype. For example, British land snails are found in low vegetation areas. The thrushes…show more content…
So, if the plant entices an animal, say a bumblebee, to come to it by offering it some sweet nectar, then plant can attach some of its pollen to the back of animal and it will carry it to a new
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