NewScientist reports on experiments that have shown that it is possible for strands of DNA to replicate, without life, near geothermal vents in deep ocean areas. That’s right — DNA replication without life. This is akin to hand-cranking a motor to get it started, then letting it run on its own power thereafter.
In air, particles typically shift into a colder current because they are more likely to be pushed away by warmer, more energetic molecules than those on the cooler, calmer side. The researchers reckon a similar process would occur in the fluid in the vents.
Over time, the DNA templates, polymerase and nucleotides would collect at the bottom of a pore. Once there, they could become concentrated enough for the polymerase to bind new nucleotides to the single-strand DNA templates, replicating the original DNA (see diagram).
To test this theory, Mast and Braun put these ingredients into tubes 1.5 millimetres long. They used a laser to heat one side of the water and create thermal convection. Sure enough, they found that the DNA doubled every 50 seconds (Physical Review Letters, vol 104, p 188102).
“Proving” abiogenesis is just about impossible, this far removed from the event in question. Guessing the exact combination that led to life on our planet might be more difficult than we’d anticipated, because it seems we keep finding plausible methods. The fact is, proving that it is possible in a number of different ways, takes a huge chunk out of the argument that the only possible way that life could have started, is if a personal deity did it through an act of will. Now that we know that abiogenesis is possible via a number of routes, that SHOULD end the argument, but unless we have some sort of ironclad proof for one particular method of abiogenesis, the argument will of course continue. And even if we do have that ironclad proof, it will probably persist regardless, while the God Squad attempts to co-opt abiogenesis as their deity’s mode of creation. That’s just a guess of course; you never know how these developments will really shape future philosophical debate.
Regardless, I’m fascinated by these developments. It gives me hope for our future — or if not our own future, possibly the future of some planet that we intentionally seed via directed panspermia. So long as life continues somewhere and somehow in this universe, I will feel as though there’s still a chance this universe will be understood and all its mysteries plumbed.