Consider the following scenario:
In a population of birds, Dr. Molly notices that brightly colored males and very dull males survive best.
Please help Dr. Molly conclude what type of selection this is AND what is most likely true about the proportion of males of intermediate coloring.
Disruptive; males of intermediate coloring make up a small part of the population.
Stabilizing; males of intermediate coloring make up the greatest part of the population.
Directional; males of intermediate coloring make up a small part of the population.
Directional; males of intermediate coloring make up the greatest part of the population.
Disruptive; males of intermediate coloring make up a small part of the population.
Based on the given scenario, the type of selection observed is disruptive selection. This is indicated by the fact that brightly colored males and very dull males survive the best.
Regarding the proportion of males of intermediate coloring, it is most likely true that males of intermediate coloring make up a small part of the population. This is consistent with disruptive selection as it favors extreme traits while reducing the fitness of individuals with intermediate traits.
Based on the scenario provided, Dr. Molly notices that both brightly colored males and very dull males survive best in the bird population. This observation suggests that there is selection against males with intermediate coloring.
To determine the type of selection occurring, there are three possibilities: disruptive selection, stabilizing selection, and directional selection.
1. Disruptive selection occurs when extreme phenotypes are favored over intermediate phenotypes. In this case, both brightly colored and very dull males are favored, indicating that disruptive selection is not likely to be the answer.
2. Stabilizing selection occurs when the average or intermediate phenotype is favored over extreme phenotypes. However, in the scenario, Dr. Molly observes that both extremes (brightly colored and very dull) survive best, which implies that stabilizing selection is not occurring.
3. Directional selection occurs when one extreme phenotype is favored over the other extreme or intermediate phenotype. In this case, brightly colored males and very dull males both survive best, meaning that there is a clear direction of selection. Therefore, directional selection is the most appropriate answer.
Now let's discuss the proportion of males of intermediate coloring. Based on the given information, Dr. Molly observes that males of intermediate coloring do not survive as well as the brightly colored and very dull males. Consequently, they are likely to make up a small part of the population. Therefore, the correct option is: Directional; males of intermediate coloring make up a small part of the population.