Why was the primitive atmosphere of Earth more conducive to the origin of life than the modern atmosphere?

1 Answer

There was a lower level of Oxygen in the atmosphere.

Explanation:

The DNA in particular can not exist in the presence of Oxygen. The name is de Oxi nucleic acid. That means no Oxygen. As DNA is essential to life the presence of Oxygen makes life occurring by accidental random processes difficult if not impossible.

The best empirical evidence is that the early atmosphere came from the emissions of volcanos. Volcanic gases contain large amounts of sulfur, carbon dioxide , and water. Water breaks down into hydrogen and Oxygen in the atmosphere.

The Miller Stanley experiments created some proteins needed for life by proposing a reducing atmosphere as the early atmosphere. The best present evidence is that the early atmosphere was an oxidizing atmosphere. (sulfur and oxygen are oxidizing agents.)

The early atmosphere was with less Oxygen than the present atmosphere with approximately 20% Oxygen was more conducive to life than the present atmosphere. However the indications are that the most likely early atmosphere was not at all conducive to the accidental origin of life.