Types of Natural Selection

Sparrows produce an average of 5 eggs in each clutch. If there are more than 5, parents can't adequately feed the young. If there are fewer, predators may destroy the entire clutch. This is an example of what type of selection?

• Stabilizing Selection

• Directional Selection

• Disruptive Selection

In seed cracking birds, there is an occurrence of large or small beak sizes, with medium sized beaks being absent. This is an example of what type of selection?

• a. stabilizing selection

• b. directional selection

• c. disruptive selection

Larger squirrels can carry larger acorns to their burrows, and they outcompete smaller squirrels when acorn supplies are limited. What type of selection will most likely occur?

• a. stabilizing selection

• b. directional selection

• c. disruptive selection

Panthers with teeth that are too short have difficulty capturing prey, while panthers with teeth that are too long have difficulty chewing their food. What type of selection will most likely occur?

• a. stabilizing selection

• b. directional selection

• c. disruptive selection

The rocks at the bottom of a stream are either black or white. Snails that live on these rocks are a range of color from solid black to gray to solid white. A local fish loves to munch on these snails, but it can't see the solid black or solid white snails when the snails are on matching rocks. Gray does not blend into either rock color and is much easier to see. What type of selection will most likely occur?

• a. stabilizing selection

• b. directional selection

• c. disruptive selection

Human babies usually do not survive if they are born under 4 pounds because their organs are too small to work properly; they cannot be born if they are too big because the mother would not be able to give birth without dying. What type of selection will most likely occur?

• a. stabilizing selection

• b. directional selection

• c. disruptive selection

What type of selection is depicted in the picture? 

• stabilizing 
• directional 
• disruptive 
• the answer is not here

_{What type of selection?}

• Directional 
• Stabilizing
• Disruptive