The earliest oxygen-breathing bacteria (Evolution)

by David Turell , Monday, October 24, 2011, 01:03 (4778 days ago) @ romansh

My guess would be the early atmosphere would have been fairly reducing, SO2 and methane. So any early oxygen produced would have been mopped up. Only once the reducing character of the atmosphere had been "neutralized", only then could any significant increase in oxygen content be observed.

Exactly right. I don't remember the currently proposed mixture of the early atmosphere but it has been definitely shown that the Urey-miller 'lightning in a bottle' atmosphere mixture they used was wrong.