Evolution of Genetic Material??

OK Coledude,I’ll have a stab at this one, although I’m probably not too up to date with current thinking so I might not get it quite right (but I’m sure they’ll be helpful individuals out there who will correct me if I do stray ).You’re half right about RNA, its’ a damn useful molecule: it can fold in all sorts of shapes to provide all sorts of functions but one thing that it doesn’t do very well is act as a template. The biggest advantage that DNA has is that, because it forms a double helix, it is a more stable form of storing the sequences of bases required for this variety of activities. There is not too much difference at all between the chemical structure of RNA and DNA: a missing oxygen molecule and a slightly different base! So we have a distinct advantage and a relatively small change to get that advantage — no need to invoke the magical intelligent designer at all, good old selection comes into play.Imagine a scenario in which a self-replicating RNA molecule has a sequence which gives it an advantage (enzymatic activity or help with replicating for example) and during the course of events in its environment the ribose on the template strand turns into deoxyribose. Because the storage material is now more stable, it can still produce the ribozymes (or whatever) but lord it over the other RNA molecules, so it will produce more of them — another advantage. Soon RNA on its’ own won’t stand a chance and the only thing you have is RNA sequence being carried on DNA: essentially what we still have in living organisms.Hope this is clear (I really should be in bed)Toodle oo