[Comment 8](/articles/645056-writing-a-new-code-for-life/comments?page=1#comment_920794) by  [Degsy](/profiles/43401)          :


                 Not that there is anything wrong with carbon chauvinism, after all it's the only way of life we know, but could other elements offer the complexity and diversity of compounds to allow life to occur. I recall silicon being a candidate due to its tetrahedral chemistry. The modification of bases is one thing (TNA), but does anyone know of other theories pertaining to an origin of life that does not require carbon? Just curious.

Silicon's chemistry is similar to carbon, yes. But it is a larger atom and as such, bonds are formed further away from the nucleusouter orbitals. That's not generally a problem for single bonds, but it means that double bonds and aromatics contain nodes, making them less stable. Double bonds and/or aromatics are found in practically all key biological molecules including amino acids, sugars, fats and yes, DNA and RNA.

I'd be happy to be proven wrong, but I would argue carbon's properties are so unique as to make it an absolute necessity for life.