Analysis of ancient rocks dating back 2.5 billion years ago indicated that there was oxygen present in the Earth's atmosphere around that time. The results of the study push back the previous theory that the Earth filled up with oxygen about 100 million years later than the age of the rock, implying that life on Earth may have started earlier than previously thought.

The "Great Oxidation Event" was the tipping point of Earth's history when oxygen began to appear, creating the foundation for life. The theory before the discovery of the 2.5 billion year old rock in Australia was that the appearance of oxygen on Earth was sudden, caused by organisms who evolved a little too fast (like the X-Men) and started photosynthesizing.

The discovery of the rock indicates that life began much earlier, and therefore this gives the timeline for life's evolution to relax a little. This means that life may have evolved more gradually instead of a sudden burst of prolific mutant photosynthesizing bacteria. Geologist Robert Creaser explains:

Our research indicates there were oxygen-producing organisms for many millions of years before the Great Oxidation Event, and then perhaps a 'tipping point' was reached, which launched the Great Oxidation Event.