Researchers looked at 52 samples, 2.75 to 3.2 billion years old, which had been collected in South Africa and northwestern Australia. They are by excellence among the oldest rocks on our planet.
We might have to take a second look at the evolution of life on earth.
A study on ancient soils has shown that oxygen was present on earth about three billion years ago, pushing evolution of oxygen-breathing organisms back in time. The study also supports the idea that life might have evolved on other planets.
The appearance of oxygen changed the way life evolved on Earth. Until, now researchers believed that the Great Oxygenation Event- a dynamic period of oxygen accumulation- occurred about 2.3 billion years back. The latest study argues that this event might have occurred 700 million years earlier than previously believed.
The origin of life on earth is still a matter of debate. What we do know is that cyanobacteria- a class of bacteria that photosynthesize and release oxygen introduced the gas to the atmosphere.