What occurs when too much of a population relys on something.

What occurs when too much of a population rely on something?

This leads to overcrowding after which competition sets in and it would diminish the resources and death of the unfit organism while the fittest survives.

Explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.