The accepted timeframe for the beginnings of life on Earth is now being questioned by a Curtin University of Technology led team of scientists, after finding a key indicator to the earliest life forms in diamonds from Jack Hills in Western Australia... The Curtin led team's discovery of very high concentrations of carbon 12, or "light carbon" within these crystals is remarkable as it is a feature usually associated with organic life... Evidence for ancient life stretches back in time to at least 3.5 billion years ago, in the form of single-celled organisms that did not require oxygen. The discovery...