Which type of selection tends to increase genetic variation?
A: Disruptive selection
Bl: Directional selection
C: Stabilizing selection.
The correct option is A.
Why option B is wrong:
Directional selection is a kind of natural selection in which extreme phenotypes are preferred over other phenotypes. Directional selection mostly occurs during environmental changes, mainly when the population migrated to other countries.
Why option C is wrong:
Stabilizing selection is a kind of natural selection in which the population stabilizes on the non-extreme trait value. Stabilizing selection usually uses negative selection against extreme traits. It is the opposite of disruptive selection because of favours the intermediate variants instead of extreme variants.
The selection, which tends to increase genetic variation, is Disruptive selection. It is because the disruptive selection reduces phenotypes near the average, and it favours the extreme phenotypes, which results in increasing the genetic variation within the population.
Natural selection is the driving force of evolution, which increases the frequency of genes to promote reproductive success on a larger range within the population. The natural selection can either increase the variation, reduce it, or shift the mean value of the trait.
The type of selection which increases the variation is called disruptive selection.
In disruptive selection, those individuals who have extreme values for a trait have greater success in reproduction than those individuals who have intermediate values. It is because the variation of the trait increases in the resulting population.
For instance, the tadpoles’ population is different in shape from a round omnivore and carnivore type.
The extremes of this range of Tadpoles were better at taking food. Therefore, they were more successful in reproduction than those who were closer to the middle range, which increased the variation of the coming generation.