KHARAGPUR: A team of researchers from IIT Kharagpur has found evidence of life in India dating back at least 2.5 billion years — to the beginning of a time known to scientists as the Great Oxidation Event, which marked the entry of oxygen in Earth’s atmosphere, making life, as we know it, possible.The first signs of life have been found in the form of microbial cells in the Deccan, and it took the team four years of arduous work. Finally, the microbes were found at a depth of three kilometres. The findings have been published in the December edition of “Scientific Reports: Nature”, an online, open-access journal from the publishers of the prestigious “Nature”, one of the most recognisable scientific journals in the world.The news has stunned the ministry of earth sciences, which had asked the IIT team —led by Pinaki Sar, of the faculty of biotechnology — to probe the beginning of life in India. An official announcement is expected shortly.Sar said these microorganisms, mostly bacteria, date back to a time when Earth’s crust was still unstable and earthquakes, punctuated with volcanic eruptions, were routine. Between 2.5 billion years and 65 million years ago, the crust would intermittently cool but would be shaken up again with fresh eruptions and lava flow. These cool interludes were the time when the first life forms, in the form of microbes, started making their appearances. The Deccan Traps, where the country’s oldest rocks (granites and basalt), are located, were home to these first life forms, much like the Witwatersrand in South Africa, Colorado river basin in the US, and Fennoscandian Shield, Finland. Geoscientists across the world are trying to reveal life antiquities on Earth and the discovery by the IIT scientists could well be a landmark, said sources.The search started in 2014, when the ministry asked the IIT biotechnologists to join a team of geologists at Koyna, in Maharashtra (in Karar village), where a devastating earthquake had occurred in 1964. These geologists were trying to establish the cause of the quake. Since this part of the Deccan is made of the oldest igneous rocks, the ministry asked the IIT scientists to explore the possibility of life deep inside the rock belly. These are hard, near-impermeable rocks where very little water or nutrients had percolated to make life possible.“The depths of these ancient rocks do not have oxygen, water, organics or light to support life. The rock cores we dug out from three boreholes were investigated and we have been able to prove microbial existence. It is obvious that they fought extreme conditions to stay alive and multiply,” said Sar.Sar said the next phase of their research will focus on whether the organisms are still alive. “We cannot immediately confirm that,” he explained, calling the microbes “extremophiles” because they survived extreme conditions. They are extremely intelligent bacteria and they could teach us a lesson or two about how carbon and inorganic sources can be used for survival,” he added.