Earth took its first breath 700 million years EARLIER than first thought, chemicals in three billion-year-old soil suggest
- Previous studies had suggested oxygen appeared about 2.3 billion years ago
- The latest findings imply oxygen from photosynthesis began much earlier
- They also suggest that it took longer for geological and biological processes to conspire and produce the oxygen rich atmosphere we have today
By Daily Mail UK
Oxygen arrived on Earth up to 700 million years earlier than previously believed - suggesting life took a very long time to evolve.
Chemicals in three billion year-old soils and rocks from South Africa - the oldest on the planet - indicate low concentrations of the gas in the atmosphere at this time.
The researchers detected signatures of chemical reactions that happened in the rocks three billion years ago which involved trace amounts of atmospheric oxygen.
Oxygen arrived on Earth up to 700 million years earlier than previously believed
- suggesting life took a very long time to evolve
THE GREAT OXYGENATION EVENT
The Great Oxygenation Event, also called the Oxygen Catastrophe or Oxygen Crisis or Great Oxidation, is the name given to the first appearance of free oxygen in Earth's atmosphere.
Previous geological, isotopic, and chemical evidence had suggested this major environmental change happened around 2.3 billion years ago.
A new study now suggests that the process began very early in Earth's history- around 700 million years earlier than previously believed.
The metal chromium responds to changing levels of oxygen in the air - the more there is the more electrons in each atom.
The researchers used mathematical models of these chemical reactions to estimate just how much oxygen the atmosphere contained—a fraction of a per cent of today’s atmospheric concentrations.
Previous studies suggest oxygen began accumulating only about 2.3 billion years ago during a dynamic period in Earth's history referred to as the Great Oxygenation Event.
Dr Sean Crowe, of British Columbia University in Canada, said: 'We've always known oxygen production by photosynthesis led to the eventual oxygenation of the atmosphere and the evolution of aerobic life.
'This study now suggests the process began very early in Earth's history - supporting a much greater antiquity for oxygen producing photosynthesis and aerobic life.'
He carried out the study published in Nature while a post-doctoral fellow at Nordic Centre for Earth Evolution at Southern Denmark University in partnership with its director Professor Donald Canfield.
Today the Earth's atmosphere is 20 per cent oxygen thanks to photosynthetic bacteria which
- like trees and other plants - consume carbon dioxide and release the gas
There was no oxygen in the atmosphere for hundreds of millions of years after the Earth formed.
Today the Earth's atmosphere is 20 per cent oxygen thanks to photosynthetic bacteria which - like trees and other plants - consume carbon dioxide and release the gas.
The bacteria laid the foundation for oxygen breathing organisms to evolve and inhabit the planet.
Co-researcher Dr Lasse Dossing, of Copenhagen University, said: 'These findings imply it took a very long time for geological and biological processes to conspire and produce the oxygen rich atmosphere we now enjoy.'
'That we now have technology that enables us to detect chemical reactions of trace gases deep in Earth’s geological history is truly remarkable.'
Dr Dossing added that technology similar to that used in our study, could provide a powerful tool to search for oxygen and signs of life on planets such as Mars.