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Ladataan... The life puzzle: on crystals and organisms and on the possibility of a crystal as an ancestorTekijä: A. G. Cairns-Smith
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What is the origin of life? Molecular biology shows us one kind, but in thinking about it we must consider those generalised aspects of living organisation that are common to all conceivable forms of life. The author believes that only a combination of general biological theory and particular chemical knowledge can solve the problems of the origin and re-creation of life. This book does not fall into either the classical Haldane or Oparin schools of thought on the origin of life, but advances a thesis of its own, which, according to Professor C.H. Waddington, is one of the most important recent intellectual developments in this field.Part I considers the role of molecular biology in formulating a view of life as it exists now. Part II turns to more general aspects of the organisation of matter. In Part III the author advances his own theories on the origin of life-theories which are both revolutionary and reactionary. As he remarks, 'If my conclusions are correct it may be difficult to find the right system, but it would be easy to make a very simple organism once we have.' Kirjastojen kuvailuja ei löytynyt. |
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I've also recently been reading book called "First Life by David Deamer...published in 2011 and there is either no mention or a passing reference to Cairns-Smith's work. (He's mentioned in the biography but not in the index). I think the basic problem is that the chemists don't do soil science nor, in general, clay chemistry which is a huge field all on its own.
The overall thrust of Cairns-Smiths work is to argue that RNA must have had simpler self-organising precursors. And one ubiquitous self organising mechanism is the accretion of crystals. And the various forms of clay crystals (Montmorillonite, kaolinite, rectorite etc.) might just be a template for amino acids to hook up in sequences. He has theories about how all of this might work ...especially the evolution of organic chemicals with the aid of (also evolving) enzymes. And, I think, more recent work by Stuart Kauffman (a somewhat impenetrable writer) also shows that enzymes can evolve and become more efficient with time. Cairns-Smith makes one interesting point about added genes...that they need not be made of the same material as pre-existing genes. He suggests that the sort of genes he's been talking about "would stay together not because of structural similarity but because of functional interdependence. (As grass, sheepdogs, sheep and shepherds are often found in each other's vicinity not because they look alike but because they are useful to each other).....There may be many clever things that can be done with clay platelets, but the sub functions available to the community would be more varied still if other direct acting genetic materials such as fibrous minerals, or later, organic polymers were also included in the community."
Where are these systems now? Well, probably extinct.
In some ways the book now seems rather old fashioned but it was written only 18 or so years after the discovery of the structure of DNA and lots of the genetic machinery was then unknown ....and, I guess, we have come a long way in the last 50 years with our knowledge of biochemistry. But he has intrigued me enough for me to go back and study a bit more clay physics...I have a feeling that with the diffuse double layer of clay with ionic solutions (which always apply) that one can get something like a proton pump...and that appears to be a key ingredient for creating self reproducing molecules. I give the book four stars. It's still interesting even 50 years after publication. ( )