There are anaerobic bacteria that don’t need oxygen to survive. That was the norm before The Great Oxidation Event when cyanobacteria started releasing oxygen into the atmosphere during photosynthesis. Prior to that there was very little oxygen in the atmosphere, and anaerobic bacteria ruled the world.
After the GOE the high concentration of oxygen killed off most of the anaerobic bacteria, and what was left were organisms that made a blood truce with oxygen. Aerobic organisms gained incredible power from utilizing oxygen for metabolism, but eventually die from the accumulated damage the oxygen does to them.
So it’s theoretically possible that some of those anaerobic bacteria survived for 4 billion years and are plotting revenge against us right now?
