17. Which type of selection do each of the following scenarios describe?

a. - In an average population of oysters, darker oysters blend in more in deeper waters and crabs do not see

them. The lighter oysters blend in more in the shallow waters and the birds do not see them.

The cases represent examples of directional selection.

Explanation:

The directional selection is a type of natural selection known to benefit an extreme phenotype in a range of continuous variation. This type of selection may also lead to the loss of the phenotypes distributed in the other extreme of the variation range.