Oldest fossils point to life on Earth 4 billion years ago

The oldest fossils ever found are “direct evidence” of life on Earth 3.8 to 4.3 billion years ago, researchers report in the journal Nature.

Even at the lower end of the spectrum, “the microfossils we discovered are about 300 million years older” than any runners-up, says Dominic Papineau, a professor at University College London who made the discovery.

The fact that life kick-started not long after Earth formed suggests it could also emerge on watery worlds outside our Solar System at comparable stages of formation, the scientists say. Earth and Mars had liquid water on their surfaces at the same time, notes lead author Matthew Dodd, a graduate student at the London Centre for Nanotechnology. “We could expect to find evidence for past life on Mars four billion years ago,” he says.

The tiny fossils — half the width of a human hair and up to half-a-millimetre in length — found in rock formations in Quebec, Canada, take the form of blood-red tubes and filaments formed by ocean-dwelling bacteria that fed on iron. Locked inside white, flower-like quartz structures known to harbour fossils, they were found along what were once warm-water vents on the ocean floor, most often in deep waters.

— AFP