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"Cyanobacteria have long attracted scientists' attention. Capable of photosynthesis,[2] these microorganisms have played a major role in Earth's history, in particular by contributing to the oxygenation of the atmosphere. Some cyanobacteria are able to form calcium carbonate[3] outside their cell, especially those associated with stromatolites, carbonate rocks that date back some 3.5 billion years and are among the earliest traces of life on Earth. Fossil cyanobacteria should therefore be present within this type of formation. However, the first fossil cyanobacteria go back a mere 700 million years, well after oxygen levels in Earth's atmosphere started to rise some 2.3 billion years ago.

A French team[1] may have found the reason for this long time lapse. In stromatolites collected in a crater lake in Mexico and cultured in the laboratory, the scientists discovered a new species of cyanobacterium, called Candidatus Gloeomargarita lithophora. This microorganism descends from a lineage that diverged early on in cyanobacteria. Thanks to an as yet unknown biomineralization mechanism, this cyanobacterium forms intracellular calcium carbonate nanoparticles of around 270 nanometers (270 billionths of a meter). While some cyanobacteria were known to form extracellular calcium carbonate within stromatolites, their formation within the cell had never been observed. Another distinctive feature of the new species is that it accumulates strontium and barium and incorporates them into the carbonate.

This finding is significant for the interpretation of the ancient fossil record. If the cyanobacteria associated with stromatolites formed carbonates inside their cells rather than outside, they would not have been preserved in the fossil record. This would explain the time lapse between their earliest appearance (at least 2.3 billion years ago) and the oldest fossils discovered (700 million years ago). The next step is to find out why and how this cyanobacterium produces the calcium carbonate."

Näin kertoo Sciencessä 27 huhtikuuta julkaistu tutkimus. Uutisen lähteenä:
http://www.sciencedaily.com/releases/2012/05/120511101352.htm

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"Neo-Darwinism suggests that life originated over 3.5 billion years ago, yet a rich fossil record for less than roughly 600 million years commonly is claimed. Consequently, almost all the record is missing, and evidence for the most critical two billion years of evolution is sparse at best with what little actually exists being highly equivocal."

http://www.christiananswers.net/q-crs/abiogenesis.html

Näin tiede oikeasti etenee.