Oxygen, as the waste gas produced by those creatures at that time, gradually changed the environment. It forces life to adapt to this change in order to draw energy from it.
When the most primitive creatures appeared in water, there was no oxygen in the earth's atmosphere. These creatures convert water and carbon dioxide into sugar (carbohydrate) under the sunlight, which also converts the transient energy of light energy to produce a compound for energy storage. This conversion process also emits a by-product - oxygen (more specifically, oxygen, a molecule composed of two oxygen atoms, O2).
The oxygen emitted was harmful to the living things at that time. But life will adapt slowly, and some creatures will eventually add this harmful gas to their metabolism process, so that today, oxygen has become one of the most basic elements of all life. To some extent, adapting to oxygen is beneficial to biology, because aerobic reaction (aerobic microorganism) generates more energy than anaerobic reaction (anaerobic microorganism).
The oxygen produced by the earliest organisms did not immediately accumulate in the atmosphere. In fact, oxygen first reacts with iron in water to form iron oxides, which also remain in the water. It is estimated that the primitive ocean contains a large amount of iron, which absorbed the oxygen released by organisms in a billion years. It was 2.5 billion years ago that iron in the sea was completely oxidized, and then oxygen gradually entered the atmosphere; By 600 million years ago, the concentration of oxygen in the atmosphere was comparable to today's, and life was about to move to a world beyond the waters.
A series of events that affect the biological environment remind people of a representative image in the Indian theory of the origin of the universe: the dancing Shiva. Shiva God dominates both the creation and destruction of the world.