This is interesting because pretty much every naturalistic theory of abiogenesis (the creation of life from non-living matter on the early earth) requires that oxygen be absent from the atmosphere since oxygen destroys organic compounds that are exposed to it for any length of time. That's why nutritionists encourage us to consume plenty of anti-oxidants. If life emerged through purely natural processes the first organic molecules could not have been exposed to oxygen.
Here's an excerpt from the ENV piece:
If the atmosphere has oxygen (or other oxidants) in it, then it is an oxidizing atmosphere. If the atmosphere lacks oxygen, then it is either inert or a reducing atmosphere. Think of a metal that has been left outside, maybe a piece of iron. That metal will eventually rust. Rusting is the result of the metal being oxidized. With organic reactions, such as the ones that produce amino acids, it is very important that no oxygen be present, or it will quench the reaction.So, if measurements are accurate which show high levels of oxygen in the atmosphere from almost the very birth of the planet, then we're left with two explanations for abiogenesis: either the first life originated elsewhere and migrated to earth or it didn't originate as a result of natural processes alone, but received some impetus from an intelligent source.
Scientists, therefore, concluded that the early earth must have been a reducing environment when life first formed (or the building blocks of life first formed) because that was the best environment for producing amino acids. The atmosphere eventually accumulated oxygen, but life did not form in an oxidative environment.
No doubt the finding reported in ENV will give new energy to theories that life originated elsewhere and hitched a ride to earth in asteroids. Any physicalist hypothesis, no matter how unlikely, no matter how untestable, is preferable among modern thinkers to the hypothesis that there's a Mind behind the origin of life.
The irony is that almost every contemporary discovery about biology and cosmology supports the latter and makes the former more difficult to believe.