Earth’s first living organisms didn’t leave behind footprints or bite marks or bones. These single cells thrived quietly in a tiny pocket somewhere on the planet. For centuries, scientists trying to describe this earliest life have relied on evidence provided by biology, studying what features modern life-forms have in common to deduce the most primitive components of cells. By working backward, biologists have developed proposals describing when and where such simple forms of life could have arisen. But the ideas so far are guesses at best, impossible to prove.
Researchers from a different field — geology — have more recently joined in the effort. With guidance from biologists, geologists are looking to Earth’s oldest rocks to uncover traces of life left behind by the very first cells. Geologists are also pointing biologists toward unusual environments where early cells might have gained a foothold. Where the two fields intersect, more concrete scenarios regarding life’s formative years are now taking shape… Read more at Science News.