Life on Earth Before Oxygen: 2.5-Billion-Year-Old Bacteria Discovered

A bacteria fossil, which dates back to almost 2.5 billion years, has been discovered in one rock formation in Gamohaan, South Africa. Scientists are impressed as it is not like many of the bacteria and microorganisms found on Earth which thrive on the presence of oxygen, a proof that it is a microorganism that existed prior the "Great Oxidation Event" in which massive amounts of oxygen dissolved into the atmosphere.