First signs of life on Earth now even earlier

The Guardian : Samples of rock sediments dating from 3.45 billion years ago from the Pilbara region of Western Australia appear to contain the earliest evidence yet for life on Earth. Found by David Wacey of the University of Western Australia and his colleagues, the signs of complex microbial ecosystems push the date of the planet’s earliest known life back by several million years. According to Wacey, the Pilbara region has very old rock that has not been significantly disturbed by geologic processes. Other regions with similar properties that may provide further evidence of the earliest signs of life include Greenland and South Africa. When the bacteria whose presence Wacey’s team detected were alive, Earth was much hotter and mostly covered in water. The atmosphere was primarily carbon dioxide and methane. It was over 1 billion years before more complex life began to form.