Although science and technology have lots of advancement in their territory, still lot of mysteries remain. One such thing is how and when the process responsible for producing oxygen (O2) on Earth through the splitting of water molecules first began. Lately some geobiologists at the California Institute of Technology (Caltech) have found evidence of a precursor photosystem involving Manganese (Mn) that predates Cyanobacteria, the first group of organisms to release oxygen into the environment via photosynthesis.
Oxygen (O2) makes up about one-fifth the volume of Earth’s atmosphere today and is a central element of life as we know it. Although oxygen is always present in compounds in Earth’s interior, atmosphere, and oceans, but it didn’t begin to accumulate in the atmosphere as oxygen gas until well into the planet’s history. According to some geobiologists at the California Institute of Technology (Caltech), it is manganese that played the most vital role to release oxygen into the environment via photosynthesis.
Photosynthesis is the process by which energy from the sun is used by plants and other organisms to split water and carbon dioxide molecules to make carbohydrates and oxygen. On the other side, manganese is required for water splitting to work. So, when scientists began to wonder what evolutionary steps may have led up to an oxygenated atmosphere on Earth, they started to look for evidence of manganese-oxidizing photosynthesis prior to cyanobacteria.
Since oxidation simply involves the transfer of electrons to increase the charge on an atom—and this can be accomplished using light or O2—it could have occurred before the rise of oxygen on this planet.
Woodward Fischer, assistant professor of geobiology at Caltech and a coauthor of the study said, “Water-oxidizing or water-splitting photosynthesis was invented by cyanobacteria approximately 2.4 billion years ago and then borrowed by other groups of organisms thereafter. Algae borrowed this photosynthetic system from cyanobacteria, and plants are just a group of algae that took photosynthesis on land, so we think with this finding we’re looking at the inception of the molecular machinery that would give rise to oxygen.”
The geologists findings have been published in the Proceedings of the National Academy of Sciences.