In disruptive selection, the distribution curve for a trait typically exhibits a change where it splits into two or more peaks (modes) rather than shifting to one side or the other. This occurs because individuals at both extremes of the trait are favored over those in the middle. Therefore, the correct interpretation of the change observed in a distribution curve due to disruptive selection is:
2. It shifts to the right and the left.
This response indicates that the extremes are favored, leading to an increase in frequencies at both ends of the trait spectrum while reducing the frequency of the average trait.