Independent UK: Chemicals found in 3.4 billion-year-old rocks have confirmed them as contenders for the title of oldest evidence of life on Earth. Discovered in Western Australia back in 2013, the Strelley Pool “microfossils” are thought to be all that remains of ancient bacteria. But the passage of time takes its toll on all fossils, especially microscopic ones. This means any remains that are discovered are the subject of enormous debate in the scientific community.