Which of the following is an example of directional selection?
A) The birth weight at which newborn humans are most likely to survive and the average weight of newborn humans are about the same.
B) There is an increase in antibiotic-resistant strains of bacteria.
C) There is an increase in the number of different breeds of dog.
D) Garter snakes with different coloration patterns behave differently when threatened.

Question

Quizplus · Accepted Answer

Directional selection occurs when one extreme of a phenotype is favored over the others, leading to a shift in the population towards that extreme. In the case of antibiotic-resistant bacteria, the use of antibiotics selects for those individuals with mutations that make them resistant, leading to an increase in the frequency of that trait in the population.

Which of the Following Is an Example of Directional Selection