The ribotype metaphor

The 1981 paper, furthermore, pointed out that the ribotype is not only independent from genotype and phenotype, but has a logical and a historical priority over them. According to the ribotype theory, 

We do indeed need a better metaphor, and luckily there is one at hand. It is the metaphor of the cell-as-a-city, where the proteins of a cell are compared to the houses of a city, and the genes to their blueprints (Barbieri, 1981,1985). In this framework it would not even make sense to ask if it was the houses or the blueprints that came first. What came first was a third party, the inhabitants, i.e. the intermediaries between houses and blueprints in a city which correspond to the intermediaries between proteins and genes in a cell. 

Despite its intuitive appeal, the cell-as-a-city metaphor has not become anything like as popular as the chicken-and-the-egg, and it is 

Now let us take a look at these new polymers. The formation of a random chain of subunits is accounted for by the ordinary laws of thermodynamics and does not require any new physical quantity. But when a copymaker makes a copy of that chain, something new appears  

There was a time when the world was inhabited only by natural molecules, but that period did not last forever. At a certain point copied and coded molecules appeared, and the world became also inhabited by artificial molecules, by artifacts made by nature. And that was not just another step toward life. It was the appearance of the very logic of life because, from copymakers and codemakers onward, all living creatures have been artifact-makers. In a very fundamental sense, we can define life itself as artifact-making. 

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