Genetics

A few key elements concerning Evolution
About 25 billion years ago, the Universe began to form. About 4 billion years ago, life began. The conditions on Earth at the time of life’s inception are as follows:
1. Extremely hot temperatures, i.e. 800°C
2. Gases such as CH4, NH3, He, H2, and water vapours were present in the form of lighter components.
3. Heavy elements such as Fe (iron) and Nickel (Ni) are found in the Earth’s core.
4. The only source of energy was ultraviolet light, which favoured photochemical reactions.
5. During the period of evolution, there was no molecular oxygen in the atmosphere, i.e. the atmosphere was reduced.