Answer:
An unstable ecosystem refers to the state of an ecosystem when it loses the tendency to get amend with the environmental modifications. This takes place when the modifications are spontaneous and huge and these variations enhance the capacity or resilience of the ecosystem.
In the given question, that is, in the movie Lion King, one can witness the change in the ecosystem in three ways at the time when Scar replaces Mufasa as the pride. During the reign of Scar, the food sources started to decline, the water sources started to decline, and the packs of antelope started to move on due to lack of grass. Thus, the stable ecosystem gets replaced by an unstable one.
