Researchers from the United States showed that cyanobacteria developed the ability to oxygen photosynthesis, as a result of which oxygen occurs, about 2.9 billion years ago, in Archeye. The article of scientists was published in the journal Proceedings of the Royal Society B.
The beginning of the implementation of photosynthesis cyanobacteriums with the formation of oxygen – the energy basis of all alive on earth – has become an essential evolutionary breakthrough. However, the estimates when it happened, differ.
For a more accurate setting of this event, researchers from the Massachusetts Institute of Technology combined the methods of “molecular hours” – dating based on the speed of evolutionary changes – and information about horizontal transfer of genes. The detection of such non-fermented genes suggests that one group of organisms younger than the other – on the basis of which, suggested geologists, and their relative seniority can be established. Comparison of it with different ages and allows you to install the most accurate model.
Researchers managed to identify 34 cases of horizontal transfer of genes in cyanobacteria. Only one of the models of molecular clock corresponded to the ages established in the analysis of these cases. According to it, cyanobacteria separated from the remaining bacteria of 3.4 billion years ago, and their vertex group – which includes all existing species with oxygen photosynthesis – arose 2.9 billion years ago. This means, they emphasize the specialists that the production of oxygen with cyanobacteria began 500 million years to an oxygen catastrophe – a sharp saturation of the atmosphere of oxygen and its cardinal transformation. At the same time, shortly before it – 2.4 billion years ago – the number of types of cyanobacteria increased dramatically, which emphasizes the researchers, and could lead to an oxygen catastrophe.