Question

While all giraffes are tall they are not all the exact same height. Within a population, the height of each individual giraffe can vary. Scientists observe that over many generations the average height of the giraffe population is increasing. They believe this in response to trees producing fewer leaves on lower branches, meaning the giraffes' main food source is higher up.

What kind of selection is this an example of?
(1 point)
Responses

Directional Selection and Disruptive Selection
Directional Selection and Disruptive Selection
Stabilizing Selection
Stabilizing Selection
Disruptive Selection
Disruptive Selection
Directional Selection

Answer 1

This is an example of **Directional Selection**. In this case, the average height of the giraffe population is increasing over generations in response to environmental changes (i.e., food sources being higher up). Directional selection favors individuals at one extreme of the trait distribution—in this case, taller giraffes—leading to a shift in the population's traits over time.