A recent study may have resolved the debate over when oxygen began to be produced on Earth and how long it then took for levels to reach the stage where they could support the growth of life.
The study has identified how links between tectonics and ocean and land chemistry gave rise to life on earth about 2.5 billion years ago.
The research team found an increase in chromium in the banded iron formations starting 2.48 billion years ago, indicating the strong possibility of a link between life and the growth of continents. Using this data, they were able to see that cyanobacteria had started to produce oxygen during this time period.
This confirms that the 2.48 to 2.32 billion year period, known as the Great Oxidation Event, eventually enabled the formation of complex life.Read more at The University of Western Australia