Why has life evolved around oxygen? Many lifeforms require oxygen to breakdown bio-molecules and release energy. I think there are two possibilities:
- Reactions with oxygen tend to release more energy, so it is profitable to use oxygen for metabolic activities.
- It is chance that it got to be oxygen; it could have been anything.
Which is right? Or is there some other possibility?
Edit: Yes, it is true that there are organisms to which oxygen is toxic. But you can't ignore the large numbers of organisms to which it is absolutely necessary for living. Why could it not have been some other molecule? Which property of oxygen drives it to become the most useful in bio-processes?