St Andrews experts have unearthed new evidence for early life on the planet.
Chemical analyses of some of the oldest pieces of Earth ever discovered suggest the planet was habitable as early as 4.1 billion years ago – 700 million years before the date of the earliest confirmed fossil.
Until relatively recently, it was thought life on Earth must have evolved after 3.9 billion years ago, as during this time it was undergoing a period of intense meteorite attacks believed to have destroyed all potential for life.
However, earlier this year a study used a genetics-based “molecular clock” to suggest that all life on Earth evolved from a common ancestor that arose before that time.
The new research presents, for the first time, evidence the environments necessary to support life were present on Earth’s surface during this period.
Dr Paul Savage, from St Andrews University’s school of earth and environmental studies said understanding how, when and where life first arose was fundamental to understanding how life might evolve on other planets and to understanding what our earliest ancestors were.
The latest study, involving researchers at the University of St Andrews with colleagues at the University of Rochester, UCLA and the University of Oregon, has been published in Proceedings of the National Academy of Sciences.