London: The first replicating life-forms on the planet may have originated deep underground, a study has suggested.
A new research into the "deep biosphere" has shown that microbes living and reproducing as deep as 5km below ground are likely to have formed a distinct subsurface community of genetically similar individuals despite living on opposite sides of the world, and have survived in complete isolation from the surface biosphere for billions of years.
The global similarity of such an isolated life-form has suggested that they may have evolved directly from a common ancestor that lived at the period when life on earth originated, some 3.5 billion years ago.
Matt Schrenk of Michigan State University said that this research lends further support to the idea that life originated not in the "primordial soup" of surface lakes and seas, but in the tiny water-filled fissures found in underground rock.
