Signs of microbes found in 3.2-billion-year-old sandstone
Courtesy of Martin Homann, Free University of Berlin
For Earth’s early inhabitants, living in a bubble was a good thing.
Pockets of gas trapped along ancient shorelines gave microbes a cozy place to call home about 3.2 billion years ago, scientists suggest December 4 in Geology. Such a snug hideout could have shielded microbes from ultraviolet radiation not only on Earth, but perhaps on Mars as well.
The new work is “exciting and very plausible,” says geologist Frances Westall of the French National Center for Scientific Research in Orléans. “It expands the known habitats for early life.”
Earth was a tough place to live a few billion years ago. No oxygen in the atmosphere meant no ozone, and therefore no protection from the sun’s ultraviolet rays, says study coauthor Alessandro Airo, a geobiologist at the Free University of Berlin in Germany.