Cycles, Balance, and Life
For hundreds of millions of years, the chemicals and elements found on Earth have remained relatively constant, or in other words, they have changed very little. The amount of one element or chemical in the Earth’s surface is practically the same as it was many millions of years ago. This consistency is one of the things that makes life on Earth possible.
This balance is maintained via complex interactions or cycles between the Earth and its organisms, or lifeforms. The elements of the Earth are taken into lifeforms, used to sustain the organism, and later released in the form of waste, or through decomposition upon the death of the organism.
Most of these cycles only take a few months or a few years to complete. However, some can take many millions of years.