Life existed in oceans at least 200 million years before oxygen appeared on earth, a new study has revealed.
During this period in its history, known as Archaean, the earth was covered by a poisonous smog of methane, ammonia and other toxic gases. So, life as we know it today could not have survived then.
Now, an international team, led by Rutgers University in New Jersey, has claimed that plant-like bacteria existed in the oceans for hundreds of millions of years while the earth’s air was not fit to breathe.
The findings are based on analysis of ancient preserved seabed rocks from South Africa dating back some two to three billion years. The study found chemical evidence of nitrogen cycles which could not have taken place without the presence of free oxygen.