Eating

We eat and extract the nutrients from what we eat and excrete the rest. Every living thing does some form of eating. For plants and trees the food they need is carbon dioxide, the stuff that we exhale. Our excrement is also good food for plants and trees being rich in the nutrients that plants relish on. Oxygen is released by plants after they absorb carbon and this gas is something that we need to survive. Plants themselves are a good source of nutrients for animals and people. Nature has perfectly created a system which should be able to sustain itself for a long time. Nothing is ever wasted, everything is recycled if Nature were left to her own devices.

Man has invented Agriculture to ensure that food would never be scarce. He has used his intellect to construct barns and silos and storage facilities to preserve his crop and keep them from spoiling. He has become capable of producing more than he needs and so he does. What does he do with the surplus? He trades it for things that he doesn't have. So other people plant other stuff or maybe raise animals and become experts in their respective fields. Man has liberated himself from being a hunter and a gatherer. He has learned to become a specialized productive unit interacting with other productive units.

Pretty soon money was invented to facilitate the trading of goods. From the basic need to eat has evolved a complex system of commerce and trade making sure that there is always plenty to eat and this has resulted in another big bang of sorts, an explosion in population growth.