Abiogenesis (Origins)

by dhw, Tuesday, November 17, 2009, 19:50 (5294 days ago) @ George Jelliss

George has drawn our attention to an article by Dr. Vinod K. Wadhawan explaining the process of autocatalysis, which appears to offer an important contribution to the theory of abiogenesis. I'm in no position to comment on the science, which is way over my head, but for anyone who hasn't read it I'm reproducing the conclusion, which I think offers a clear summary for us non-specialists.-"The probability is next to nil that highly complex molecules like RNA, DNA and proteins got created spontaneously through purely random or chance processes. However, the nearly-impossible became possible, i.e. the unlikely set of events became likely, through the mechanism of autocatalysis. As John Avery has pointed out in his book Information Theory and Evolution (2003), 'A notable feature of autocatalysis (apart from providing a credible mechanism for the origin of life) is that it has the seeds of natural selection at the molecular level: The precursor molecules and the energy-rich molecules are 'food'. And the alternative autocatalytic systems compete for this supply of food. The efficient ones have a better chance of dominating and winning (through faster reproduction). Supply of free energy, of course, was/is the prerequisite for all this to become possible.'
Once a set of autocatalytic reactions had established itself, it went on incrementally evolving into still more complex sets of molecules. Chance events and/or new external conditions resulted in the emergence of a slightly more complex version of, say, one of the molecules in the autocatalytic set. A further round of chemical Darwinism and evolution of a new set of autocatalytic set of molecules followed. And so on, till molecules as complex as RNA, DNA and proteins emerged on the scene, which have life-sustaining and life-propagating properties.
This explanation is an important milestone in our quest for understanding in a rational manner the origin, or origins, of life on Earth. But what is life? I shall address this question in the next article in this series."-"The more we learn about the unbelievably complex, immensely varied, and yet simultaneously simple origin and development of life on earth, the more it looks like a miracle, and one that is still unfolding. The miracle of evolution." Sharon Moalem-Whether our descent from physical materials through physical processes is programmed or not, it's good to be reminded that the scientific "quest for understanding" goes on. Thank you, George, for a timely nudge. The fact that scientists are discovering more and more about these processes is exciting in itself, though I must confess I'm not so keen on Sharon Moalem's oxymoron. I'd be grateful if you would let us know when Dr. Wadhawan's next article appears.