Deeper Science of Green Slime

An anonymous reader writes: "As the source of all breathable air, and often-cited as the oldest fossils (3.5 billion years, Western Australia), cyanobacteria or green slime is discussed today in NASA's Astrobiology Magazine. The fascinating parts are the two survival paths that make cyanobacteria ductile, but not fragile (relatively unchanged since the beginning of life on Earth): sharing genes (lateral transfer) to get new capabilities for photosynthesis, and absorbing other cells by engulfment. It is the evolution by engulfment that seems so amazing as a means of species survival, since it is the opposite of parasitism."

Comments

it has to be said

[ajrs]

microsoft - the green slime of IT.

Detail from deep in the article

[Anonymous Coward]

Let's look in this discussion at some details as mentioned in the article linked in the summary

However, Schopf's finding may not be as definite as the textbooks and news reports would have you believe. Some scientists contend that the shapes found by Schopf are not cyanobacteria, or even fossilized life forms at all. Martin Brasier of Oxford University leads the opposition against Schopf's claims. Brasier says that rather than being biological fossils, these structures are chemical artifacts formed from hydrothermally-heated graphite. The debate rages on, and many scientists are conducting their own studies of the enigmatic structures in an effort to find the truth.

Another controversial topic in the debate over cyanobacteria is the existence of Archaean stromatolites. These layered rock formations are formed by cyanobacteria. The bacteria live in a colonial layer called a "microbial mat." When too many minerals and sediments became trapped in the sticky mat, sunlight can no longer penetrate and photosynthesis becomes impossible. The cyanobacteria then migrate up, creating a new mat layer on top of the old. This process occurs again and again, creating multiple sediment layers over time.

The existence of stromatolites dating back to nearly 3.5 billion years ago suggests that cyanobacteria were hard at work during the Archaean era. But not all stromatolites are formed by cyanobacteria; natural geological processes can build similar structures. Some have argued, therefore, that the ancient rock structures were formed by chemical precipitation or by the deformation of soft sediments.

Did you notice that - these structures might be chemical artifacts, or they might be geological processes. The equivocations are there, a very nice thing to see - science is rarely so open about the alternative explanations when quoted in the popular press.

Re:Detail from deep in the article

[Trane Francks]

> Did you notice that - these structures might be
> chemical artifacts, or they might be geological
> processes. The equivocations are there, a very
> nice thing to see - science is rarely so open
> about the alternative explanations when quoted in
> the popular press.

More appropriately, the popular press is rarely so open to the alternative explanations offered by science. Lucky for us, these articles are too obscure to be of much interest to the popular press. Science-oriented journals are generally less likely to try to sell with sensational headlines and more likely to get into the meat and potatoes of a particular subject.

Re:all breathable air

[.milfox]

This is quite a ways before trees evolved.

Overall, this has a pretty neat synopsis of single celled molecular evolution. And the pnas.org link was pretty cool, too. The article cites quite a bit of hard core research, but is still readable.

Re:all breathable air

[Valdrax]

If it wasn't for cyanobacteria, we'd still have a primarily methane and carbon dioxide atmosphere. Cyanobacteria can be credited with resposibility for the major atmospheric change that occured around 2.5 billion years ago as the first photosyntheic lifeforms.

Green slime is for beginners.

[zero_offset]

I was always worried more about the Gelatinous Cubes, oh yeah, and the Grey Ooze...

Terraforming

[Samus]

What prevents somebody from gathering up a can of these things and shooting them off to mars for terra forming? If we send some off now it would give us a good jump start for when we can send people there efficiently.