According to a study published in the journal Nature this September 26, our planet's atmosphere first started accumulating oxygen not 2.3 billion years ago, as previously believed, but some 700 million years earlier.
Thus, scientists working with the University of Copenhagen and the University of British Columbia claim that, while analyzing ancient soil samples collected from South Africa, they found evidence that our planet's atmosphere contained fairly low concentrations of oxygen roughly 3 billion years ago.
These findings are likely to force researchers to reconsider existing theories concerning how and when life first emerged on Earth.
“These findings imply that it took a very long time for geological and biological processes to conspire and produce the oxygen rich atmosphere we now enjoy,” says Lasse Døssing from the University of Copenhagen, as cited by Science News.
“We've always known that oxygen production by photosynthesis led to the eventual oxygenation of the atmosphere and the evolution of aerobic life. This study now suggests that the process began very early in Earth's history, supporting a much greater antiquity for oxygen producing photosynthesis and aerobic life,” specialist Sean Crowe from the University of British Columbia also points out.