In order to test hypotheses about natural selection favoring stripes in zebras or otherwise, researchers will have to assume that stripe colors are heritable in zebra.
Natural selection forces only act on heritable traits/genes so as to help organisms adapt to changes.
Traits that are developed as a result of the environment without any underlining genes are not heritable and cannot be selected or deselected by natural selection forces.
More on natural selection can be found here; https://brainly.com/question/1657375?referrer=searchResults