Proofs of life dating back 3.2 billion years!
The scientific community accepts dating back to 2.7 billion years the first uncontested proofs of life on Earth. Beyond that, it’s a real free for all. But the ULg biologist and geologist Emmanuelle Javaux and two of her American and Canadian colleagues have succeeded in pushing back this time. Their discovery: microorganisms – thus proofs of life on earth – which they have dated, with supporting evidence, to 3.2 billion years ago. A world first, well worth a publication in the journal, Nature.
It is known that life appeared on Earth very early, but scientists don’t agree on the exact date. It is nonetheless there is general acceptance with dating it to the end of the Achaean (the mid Pre-Cambrian period), around 2.7 billion years ago, after an intense period of bombardment by meteorites. Beyond that, controversy blazes furiously. But, for the first time, a team made up of the spectroscopist Craig P. Marshall, from the University of Kansas, Andrey Bekker, a geologist and geochemist from the University of Manitoba, who specializes in carbon isotopes, and the biologist and geologist Emmanuelle Javaux from the University of Liège, a specialist in micro-palaeontology, have discovered microorganisms, of a relatively large size, cohabiting with the microbial mat in the photic zone (still accessible to the Sun’s rays) in coastal sea areas dating back to…3.2 billion years ago! In plain language: incontestable proofs of life going back to this period.