The prebiotic metabolism approach

It seems that there is a missing link between the scenarios of the prebiotic RNA-world and the compartmentalishc approach and the missing link is how to make RNA by a prebiotic sequence or network of internalized reactions. 

In a way, the missing link appears to be the aim of a few distinct research groups, who are inquiring into the possibility of prebiotic metabolic pathways prior to enzymes. There is a rather complex kaleidoscope of authors and views, and it is useful to distinguish between the following main trains of thought. 

In a rather original approach, H. J. Morowitz and co-workers (Morowitz et al, 1991 1995 and 2000) examine the chemistry of a model system of C, H, and O that starts with carbon dioxide and reductants and uses redox couples as the energy source. To investigate the reachon networks that might emerge, they start 

All this sounds more like a metaphor and this is probably why the idea was so catchy - it draws on visual evidence of simple and well-known mechanisms. However, from a metaphor to a chemical reality there is a wide gap - how proteins 

Cairns-Smith s original approach may sound different from Morowitz s approach mentioned earlier but in fact it also postulates a kind of metabolism without and prior to enzymes. 

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