life, but not as we knew it

[mellowtigger]

Two of the requirements for the current definition of "life" are these: the ability to self-regulate (homoeostasis) and the ability to reproduce. It turns out that these two processes might not have to be separate.

Scientists cultivate an extremophile called Haloferax volcanii which came from the extremely salty Dead Sea.  Because it survives in that harsh environment, astrobiologists wonder if we will find its relatives in the similar environment on the surface of Mars.  A recent study into this ancient form of Earth life (called "archaea") hint that this microscopic life might be very common. It revealed that a mechanism for homeostasis can be commandeered by archaea for use in replication.  This discovery has ramifications for both astrobiology and cancer research.

Normally, a cell's daily workings result in damage to its dna, so it employs processes to repair that damage.  These micro-repair mechanisms are different from those used to produce a full copy of the dna during replication.  Archaea reveals, however, that it can induce a simultaneous bloom of micro-repairs that results in a complete copy of the original dna.

However, the Nottingham study, funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and the Royal Society, found that the Haloferax volcanii is able to spontaneously begin a chain reaction of replication all around its chromosomes even when its replication origins have been eliminated. In addition, the scientists discovered that far from being disadvantaged by having to employ this novel survival method, the archaea without chromosomal origins grew faster.

“The amazing thing that we found wasn’t just that deleting the origins still allowed the cells to grow, but that they now actually grew almost 10 per cent faster. Everybody was thinking, ‘where’s the catch?’ But we haven’t found one” Dr Conrad Nieduszynski said. “The way cells initiates this replication process is to use a form of DNA repair that exists in all of us, but they just hijack this process for a different purpose. By using this mechanism, they kick-start replication at multiple sites around the chromosome at the same time.”
- http://www.astrobio.net/pressrelease/5805/an-archaeas-unexpected-route-to-reproduction

Interesting news.  It offers a boost to the likelihood of panspermia theory being reality.  When we venture into the universe, we may find it a much "dirtier" (and thriving) environment than we envisioned a century ago.

(p.s. I chose the title as a play on Mr. Spock's analysis in Star Trekkin' lyrics from 1987.)