Lucknow: Scientists at the Birbal Sahni Institute of Palaeosciences (BSIP) have found strong evidence of some of the earliest life on Earth and how it changed earth’s environment.The evidence comes from 2.6-billion-year-old stromatolites found in Karnataka’s Dharwar craton. Stromatolites are rock-like structures made by tiny microbes (bacteria). They are among the oldest fossils on earth and show that life existed very early on the planet.The study has been published in the latest issue of the Proceedings of the Indian National Science Academy (PINSA).The research was carried out by Mukund Sharma, now a CSIR emeritus scientist at Integral University, along with BSIP scientists Yogmaya Shukla and Arif Ansari. They studied the ancient rocks using powerful microscopes and chemical tests.The scientists found signs that the carbon inside the rocks was produced by living microbes and not by natural chemical reactions. The rocks also contained tiny round structures, smaller than two micrometres, which are even smaller than the earliest known microorganisms.The findings suggest that tiny microbes were living in shallow seas more than 2.6 billion years ago, long before Earth’s atmosphere had enough oxygen.Scientists say the discovery is important because it helps answer one of science’s biggest questions — how life began and how the first microbes slowly changed earth’s environment.“This research adds an important clue to the story of early life on Earth. The ancient rocks preserve signs of microbial communities that lived billions of years ago,” said Sharma.He added that the study helps scientists understand how the earliest microbes lived and how their activities slowly changed earth’s surface and atmosphere.Although the exact type of microbes cannot be identified from their shape alone, the geological and chemical evidence strongly suggests that microbial life existed in earth’s oceans during that time.
