Oxygen appeared on Earth much earlier than thought, sample suggests. Previous studies had suggested oxygen appeared about 2.3 billion years agoThe latest findings imply oxygen from photosynthesis began much earlierThey also suggest that it took longer for geological and biological processes to conspire and produce the oxygen rich atmosphere we have todayBy Ellie Zolfagharifard Published: 17:12 GMT, 25 September 2013 | Updated: 19:04 GMT, 25 September 2013 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. Scientists Find Oldest Fossils On Earth. January 2, 2013 Brett Smith for redOrbit.com – Your Universe Online In a sun-scorched region of Western Australia known as Pilbara, a team of American and Australian paleobiologists believe they have located the oldest known evidence of life on Earth.
The ancient bacterial fossils have been dated as 3.49 billion years old, only about a billion years after scientists estimate the Earth was formed. “It´s not just finding this stuff that´s interesting,” said Alan Decho, a geobiologist at the University of South Carolina. “It´s showing that the life had some organization to it.”