Our present atmosphere consists of 78% nitrogen, 21% molecular Oxygen and 1% of other gases, such as Carbon Dioxide, Argon and water Vapour. An atmosp

• Our present atmosphere consists of 78% nitrogen, 21% molecular Oxygen and 1% of other gases, such as Carbon Dioxide, Argon and water Vapour. An atmosphere containing free oxygen would be fatal to all origin of life schemes.
• While oxygen is necessary for life, free oxygen would oxidize and thus destroy all organic molecules required for the origin of life. Thus, in spite of much evidence that the Earth has always had a significant quantity of free Oxygen in the Earth’s early atmosphere. However, this would also be fatal to an evolutionary origin of life.
• If there were no Oxygen there would be no protective layer of Ozone surrounding the earth. Ozone is produced by radiation from the sun on the Oxygen in the atmosphere, converting the diatomic Oxygen we breathe to triatomic Oxygen which is Ozone. Thus, if there were no Oxygen there would be no Ozone.