[Answer] What evidence points to the date of the appearance of the first oxygen-producing organisms?

Answer: iron oxides in rock

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What evidence points to the date of the appearance of the first oxygen-producing organisms? The Great Oxidation Event (GOE) sometimes also called the Great Oxygenation Event Oxygen Catastrophe Oxygen Crisis Oxygen Holocaust or Oxygen Revolution was a time period when the Earth's atmosphere and the shallow ocean first experienced a rise in oxygen approximately 2.4–2.0 Ga (billion years ago) during the Paleoproterozoic era. Geological isotopic and chemical evidence … Before photosynthesis evolved Earth's atmosphere had no free oxygen (O 2). Photosynthetic prokaryotic organisms that produced O 2 as a waste product lived long before the first build-up of free oxygen in the atmosphere perhaps as early as 3.5 billion years ago. The oxygen they produced would have been rapidly removed from the oceans by weathering of reducing minerals [citation needed] most ... Geological history of oxygen - Wikipedia History of Earth - Wikipedia Great Oxidation Event - Wikipedia Geological history of oxygen - Wikipedia The evolution of photosynthesis refers to the origin and subsequent evolution of photosynthesis the process by which light energy synthesizes sugars from carbon dioxide and water releasing oxygen as a waste product. The process of photosynthesis was discovered by Jan Ingenhousz a Dutch-born British physician and scientist first publishing about it in 1779. The Cambrian explosion or Cambrian radiation was an event approximately in the Cambrian period when practically all major animal phyla started appearing in the fossil record. It lasted for about 13 – 25 million years and resulted in the divergence of most modern metazoan phyla. The event was accompanied by major diversifications in other groups of organisms as well. The first eon in Earth's history the Hadean begins with the Earth's formation and is followed by the Archean eon at 3.8 Ga.: 145 The oldest rocks found o...

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