AUSTRALIAN NATIONAL UNIVERSITY, YURI AMELIN

Fossils recently discovered in Greenland contain evidence of the earliest known life on earth—dating to 3.7 billion years ago (bya), claim researchers who have been studying the finds. The minute, sedimentary remains, called stromatolites, of microbial colonies that grew on an ancient shoreline are described by a team of Australian researchers in a paper published this week (August 31) in Nature.

“The approximately 3.5-billion-year-old stromatolites in sedimentary rocks of Western Australia are currently regarded as the oldest evidence of life on Earth, and pushing the record further back in time had seemed unlikely because there is almost no rock remaining from the earliest period of Earth’s history,” writes Abigail Allwood of the California Institute of Technology in an accompanying commentary. In this extraordinarily rare find, researchers have done just that.

The fossils corroborate previous evidence from genetic molecular clocks that places the origin...