Tuesday, February 07, 2012
Chemical factory model of "physical cemistry" life
I must admit that when I say I *really* liked These metabolism posts, it doesn't mean I agreed with all the things that I thought were completely non-sequiters. These posts rightly say that without an explanation of how metabolism is being performed, talking about how complex chemicals can be reproduced is an excercise in formula manipulation and wishful thinking chemistry. The most crucial part of these posts is the energy graph and pictures showing the inside and outside, and tight logic that pretty much states, that if this cannot happen, life will not happen. Also the bit which states that we should start with what we think physical chemistry life would look like, and see how it could progress, is fair enough. However, I also think that metabolism without reproduction is just as useless. The metabolic process has to reproduce itself, or at least be produced with a process that continues virtually forever through time, such that there will always be appropriate metabolic systems. The system must somehow also build information, whatever that means. In my "chemical factory" model of life, the thing which is reproducing (a molecule of some kind) is not the of the same scale as that which is providing the metabolism (chemical factory). Just imagine a factory which is producing widgets of random size and shape, not knowing if they will ever be used in anything. Energy is going in, and the rest of the Universe is being made random, and certain widgets are being produced depending on the type of energy being applied, seed molecules available, and what molecules are escaping into the rest of the Universe. Certain factories are making one type of molecule preferentially, while others are making others preferentially. Every now and then a molecule or group will be thrust from one to another factory, altering the seed stock and affecting which chemicals are more predominant. These "factories" could be any size - Molecular cloud sized, planet sized, asteroid sized, football field sized, golf ball sized, ball bearing sized - you get the drift. It doesn't really matter. What matters is the previous mentioned requirements for them to demonstrate metabolism as described in the metabolism posts. Energy in, waste out, outside more random, inside less random. It is not hard to see, that at some scale, in some conditions, it would be life generating metabolism.