In 1953 SL Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include
| 1. | low temperature, volcanic storms, atmosphere rich in oxygen |
| 2. | low temperature, volcanic storms, reducing atmosphere |
| 3. | high temperature , volcanic storms, non-reducing atmosphere |
| 4. | high temperature , volcanic storms, reducing atmosphere containing CH4, NH3 etc. |