https://www.vice.com/en_us/article/v7bjnj/scientists-just-made-a-discovery-about-the-origin-of-life

The origins of life on Earth are still mysterious, but scientists have just taken another step toward understanding how and when complex organisms emerged on our planet.

As reported in a new study, scientists have found the oldest direct evidence of oxygenic photosynthetic structures—ones capable of turning sunlight, water and carbon dioxide into energy and oxygen—inside fossilized bacteria from Australia and Canada. The fossils are 1.75 billion years old, pushing back the undisputed origin of photosynthesis as we know it by at least 1.2 billion years. This key process helped life along by pumping the atmosphere full of oxygen.