Answer:
- Gases from Earth's surface form the atmosphere
- Earth's surface cools
- Photosynthetic organisms absorb atmospheric carbon dioxide and release oxygen
- The composition of Earth's atmosphere changes.
- Organisms with aerobic metabolism evolve
Explanation:
According to the <u>chemosynthetic hypothesis of the origin of life</u>, gases such as methane, hydrogen, water vapor, etc. that emanate from the earth's interior formed the atmosphere of the primitive earth.
The earth's surface was characterized by volcanic activities and as it cools down, the water vapor in the atmosphere began to condense and form puddles of water on the surface of the earth. A chemical soup was later formed from the dissolution of the atmospheric gases catalyzed by heat, lightning discharge, and UV rays.
From the chemical soup, the first organism with heterotrophic metabolism evolved, and as the evolution continued and resources became limited, autotrophic organisms emerged and are able to utilize carbon dioxide and water to photosynthesize and release oxygen as a by-product.
As oxygen gradually gets to the atmosphere, the composition of the earth's atmosphere changed and organisms with aerobic metabolism evolved.
