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

Disruptive Selection
Disruptive Selection

Directional Selection and Disruptive Selection
Directional Selection and Disruptive Selection

Directional Selection
Directional Selection

Stabilizing Selection

Answers

GPT-4o mini
This is an example of **Directional Selection**.

Directional selection occurs when individuals at one extreme of a trait (in this case, height) have a higher fitness due to changing environmental conditions, leading to an increase in that trait's average value over generations. In the case of giraffes, the increasing average height is a response to the availability of food in higher branches, favoring taller individuals.