Oldest proof of Earth's photosynthesis dates back 1.75 billion years

Scientists have uncovered ancient microfossils that provide important information about the origins of photosynthesis. These tiny fossils, which have been conserved for over two billion year within ancient rocks, are believed to be the oldest known evidence of photosynthesis on Earth. The researchers found microscopic thylakoid structures in the McDermott Formation in Northern Australia's arid regions and believe these are remnants of cyanobacteria, preserved in fossil form, dating back approximately 1.75 billion years. Cyanobacteria are photosynthetic minuscule organisms. Photosynthesis is a crucial chemical process for energy production in green plants, algae and some bacteria. Researchers propose that photosynthesis started at least 1.75 billion years ago. Thylakoids, vital in cyanobacteria's photosynthesis process, were discovered in well-preserved conditions in Australia's McDermott Formation fossils. These findings may aid in understanding the Great Oxidation Event, a notable period in Earth's history when oxygen levels in the atmosphere dramatically rose. The study suggests that cyanobacteria with thylakoids might have played a considerable role in the Great Oxidation Event, which happened about 2.4 billion years ago. Understanding cyanobacteria's evolution, especially the formation of thylakoid membranes, is crucial in deciphering Earth's past and the development of oxygen in the atmosphere. The scientists aim to find more ancient evidence of thylakoids in even older rocks. Further studies may help understand the link between the identified microfossils and today's cyanobacteria.