In a population of parrots on an island,there is considerable variation in beak size.Parrots with small,thick beaks can efficiently eat locusts (insect),while birds with long,thin beaks can efficiently eat beetles.Both food types are available on the island.Which of the following types of selection,and effects on phenotypic variation would you expect to see?
A)Directional selection;phenotypic variation decreases.
B)Directional selection;phenotypic variation increases.
C)Disruptive selection;phenotypic variation decreases.
D)Disruptive selection;phenotypic variation is maintained.
E)Directional selection;phenotypic variation remains the same.

Question

Quizplus · Accepted Answer

Disruptive selection would be expected because there are two distinct food sources that require different beak sizes. Parrots with small, thick beaks will be selected for if they are eating locusts, while parrots with long, thin beaks will be selected for if they are eating beetles. This will lead to a split in the population with two distinct groups, each with different beak sizes. Phenotypic variation will be maintained in this scenario.

In a Population of Parrots on an Island,there Is Considerable