Oldest fossils ever found show life on Earth began before 3.5 billion years ago

It took more than 10 years of painstaking work, grinding an Australian rock containing fossils smaller than the eye could see, to confirm the earliest direct evidence of life on Earth, scientists said Monday. The 3.5-billion-year-old fossils — many narrower than a human hair — are described in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal. Other teams of scientists have reported even earlier signs of fossil life, going back 3.95 billion years. But those studies are based on either an apparent shape of a microfossil, or a chemical trace — not both. “None of these studies are regarded as proof of life,” lead author John Valley, professor of geoscience at the University of Wisconsin-Madison, told AFP. “This is the first, oldest place where we have both morphology and the chemical fingerprint of life.”