Unformatted text preview: Directional Selection • In directional selection the population consistently shifts toward a phenotype that is favored at the expense of others. This differs from stabilizing selection where extremes are reduced at both ends of the variation continuum. • Directional selection is typically a response to a changing environmental condition or to a new environment. • Some examples of directional selection include: • Peppered moth mentioned earlier is a dimorphic population where the shift has been to the dark form in response to pollution • Resistance to pesticides is common in many organisms • Most induced selection or artificial selection is directional. We narrow the population for some characteristic....
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- Spring '10
- Evolution, coelocanth. Horseshoe