What happens when an ecosystem reaches the maximum number of individuals it can support

A collapse of the population is rotting, food is not enough and livelihoods have become unfeasible to decrease the number of individuals again.

Another way is to generate mutations to generate a species more vulnerable to decreasing numbers.

In this way the overpopulation is controlled.

Explanation:

In ecosystems, if an increased population breaks the balance of this and begins a new constant adaptation of the extinction of some and overpopulation of others, which may be some chains break or remain unstable.