Question

A population of field mice is preyed on by a group of hawks. The mice that are smaller in size can quickly escape into the burrows in the ground and avoid predation. The mice of medium and large size are too large to fit into the burrows and unable to escape the hawks. Over time, the mouse population is composed of mostly small mice.
What process is responsible for causing this outcome?
(a)Hardy -Weinberg equilibrium
(b)Diversifying selection
(c)Stabilizing selection
(d)Directional selection
(e)Sexual selection

Answer 1

Evolution is the change of biological characteristics which are expressions of genes that are passed from one parent to offspring during reproduction. It occurs when evolutionary processes act on variation which results in certain characteristics becoming more common or rare within a population.

Complete answer:
Directional selection is responsible for causing this outcome. The mice that are smaller in size can avoid predation because they can quickly escape into burrows in the ground. The large mice are not able to escape the hawks as they cannot fit into the burrows. It shows that the small mice can survive because of their smaller size which makes them adapt to the conditions of predation. The allelic frequency gets shifted towards the directional selection. The advantages allele under the directional selection increases as a consequence of differences in Survival. The reproduction among phenotypes increases under directional selection.

Additional Information: Hardy-Weinberg equilibrium: The principle of Hardy-Weinberg equilibrium states that the genetic variation in a population in the absence of disturbing factors will remain constant from one generation to the next. When mating is random in a large population the law predicts that genotype and allele frequencies will remain constant because they are in equilibrium. The principal can be disturbed by several forces which include mutations, natural selection, mating randomly and genetic drift and gene flow. therefore the equilibrium describes an idealized estate and genetic variations in nature which can be measured as changes from the equilibrium state.
Diversifying selection: It is also known as a disruptive selection in which the population genetics have extreme values for a trait that are favoured over intermediate values. The variety of the trait that increases in the population and the population is divided into two distinct groups.
Stabilizing selection: The population stabilizes on a particular non-extreme trait value in the stabilizing selection and the common mechanism of action for natural selection. It is a type of natural selection. This is because of most traits that do not appear to change drastically over time. Stabilizing selection is the opposite of disruptive selection which favours the individuals with extreme phenotypes favour the intermediate variants.
Sexual selection: Sexual selection is the mode of natural selection. The members of one biological sex mates involve with other sex mates in the sexual selection which are known as the intersexual selection and compete with members of the same sex to members of the opposite sex which is known as intrasexual selection.
So, the correct answer is 'directional selection'.

Note: At one point of time whales walked on land. There are 340 breeds of dog which all came in one kind of wild wool that existed many years ago. If an animal belongs to the same species of another animal then no two animals are the same. The five-finger bone structure in humans shares the same with lots of other animals that have wings, paws or flippers.