Life appeared on Earth 60 million years earlier than was previously thought, according to a geological survey that found traces of life forms in layers of ancient soil of India.
The moment when the earth’s atmosphere became oxygen rich and life favorable, known as “the great oxidation event”, it is believed to have taken place about 2.4 billion years ago. But geologists in Ireland and India have recently found evidence of such an oxidation event much shorter, which took place 600 million years ago.
Researchers say that another study suggests that the first forms of life that produced oxygen began to develop on Earth 60 million years earlier that it was previously thought.
Scientists say that these life forms are responsible for adding oxygen in Earth’s atmosphere, a cornerstone for the evolution of life.
Indian geologists have found evidence of chemical alteration of rocks that led to the formation of very old soil, and this alteration could be done only in the presence of oxygen.
Using the knowledge of the degradation of an isotope of uranium, which in time turns into lead, scientists were able to determine the age of the soil to at least 3.02 billion years.
The studied soil comes from the Singhbhum Craton area in Odisha, India, a region where part of the crust remained stable and unchanged for billions of years.