How does adaptation affect health of an ecosystem

What could potentially occur is a species establishes an adaptation in which the population of said species could increase, thus destabilizing the natural balance of consumers of all trophic levels within that ecosystem. Ex: A species of deer acquires a resistance to disease and infection via ticks, their population would naturally increase, subsequently increasing the amount of predators (since the predators' food source would increase) as well as a decrease in the food source of the deer species (since the deer food source would not be able to keep up with the increase in deer population).