Ecosystems
All of life is connected: everything that lives depends on something else living to survive itself. Humans are no exception. All of the food we eat depends on other organisms, from the insects pollinating the plants producing fruit and vegetables to the fungi that decompose dead vegetation to provide nutrition to the soil, to the trees that provide habitat and produce the oxygen we breathe. Just like a house of cards, when one card topples, it destroys the entire tower.
