Question

Define the following terms in grammatically correct sentences. Each definition should contain the following words: population, selection, fitness, and environment.
(a) Directional selection
(b) Disruptive selection
(c) Stabilizing selection.

Answer 1

Answer/Explanation:

a. Directional selection is a form of natural selection that occurs when the conditions of an environment favors individuals of a population with an extreme trait that makes them have a fitness greater than other individuals with traits of lesser fitness that cannot survive and thrive well in the environment like the individuals with extreme traits that has greater fitness. In directional selection, the environmental condition of an environment favors the selection of individuals with a particular extreme trait only as against others with traits of less fitness.

b. Disruptive selection occurs when selection favors individuals of a population with extreme traits that has greater fitness to survive in an environment, while individuals of average traits with less fitness are selected against. Selection favors individuals of extreme values at both end of the spectrum.

c. Stabilizing selection occurs whereby, selection favors individuals of intermediate or average traits that has greater fitness to survive in an environment , while individuals in the population with extreme traits that have less fitness is selected against.