Fossils called Earth’s oldest

Tiny, tubular structures uncovered in ancient Canadian rocks could be remnants of some of the earliest life on Earth, scientists say.

The straw-shaped “microfossils,” narrower than the width of a human hair and invisible to the naked eye, are believed to come from ancient microbes, according to a new study in the journal Nature. Scientists debate the age of the specimens, but the authors’ youngest estimate — 3.77 billion years — would make these fossils the oldest ever found.

Claims of ancient fossils are always contentious. Rocks as old as the ones in the new study rarely survive the weathering, erosion, subduction and deformation of our geologically active Earth. Any signs of life in the rocks that do survive are difficult to distinguish, let alone prove. And some researchers dispute the age of the materials examined in the new paper.

But the scientists behind the study say their analysis should hold up to scrutiny. In addition to structures that look like fossil microbes, the rocks contain a cocktail of chemical compounds that is almost certainly the result of biological processes.

If the findings are confirmed, they will boost the belief that life arose very early in the history of Earth — and may find it just as easy to evolve on worlds beyond our own.

“The process to kick-start life may not need a significant length of time or special chemistry, but could actually be a relatively simple process to get started” said Matthew Dodd, a biogeochemist at University College London and the paper’s lead author. “It has big implications for whether life is abundant or not in the universe.”