Tracking Down the First Oxygen Users

sciencehabit writes "None of us would be here today if, billions of years ago, a tiny, single-celled organism hadn't started using oxygen to make a living. Researchers don't know exactly when this happened, or why, but a team of scientists has come closer than ever before to finding out. They've identified the earliest known example of aerobic metabolism, the process of using oxygen as fuel. The discovery may even provide clues as to where the oxygen came from in the first place."

Where the oxygen came from...

[jeffmeden]

The discovery may even provide clues as to where the oxygen came from in the first place.

Shouldn't they be looking for the carbon dioxide eaters?

Re:Oxidizer, not fuel

[Aguazul]

In a hydrocarbon atmosphere, you can burn oxygen. All our definitions are oriented around our oxygen-based atmosphere. I'm sure we'd call oxygen 'fuel' if we lived in a hydrocarbon atmosphere and oxygen was the scarcer material.