3.5-billion-year-old rock found in India may have oldest direct proof of life

Researchers may have found one of earliest direct signs of life on Earth in 3.5-billion-year-old rock discovered near Bhitardari village, around 20 km south of Jamshedpur. The study identified chemical signatures of biological activity in a carbon-rich, layered rock called chert. Finding such evidence is difficult as ancient rocks have been altered by heat and pressure over billions of years.