Very interesting, thanks Mark.

I wonder if DNA is a "forced result" for living things, or if there are other means by which growth, reproduction and evolution could have been mediated. In other words, is DNA the only reasonably likely organic solution to this problem? It may be a case of convergent development, such as the similarity in shape of dolphins and sharks - faced with a similar problem - rapid and manoeuverable motion through water - these two organisms arrived at quite similar solutions.

It seems that amino acids form naturally under certain conditions, and the same ones are formed repeatedly. Not all of them are used for building proteins, but I'm sure tht's not random chance - some are just not chemically suitable and so are not used, despite being avaialble in a primordial soup. Given this, and that amino acids are in fact able to form complex proteins, it may be that amino acids "invented" RNA, and later DNA. In that case, DNA may be an almost inevitable component of complex life, no matter where, when or how it originated.