I've read in some science magazine that DNA could have also evolved from a more simple type of DNA.
I think you are referring to the idea that the immediate precursor to DNA based life was RNA based. RNA has been shown to be able to self-catalyze. That is, it can promote it's own chemical formation. DN A cannnot and would require a reproduction mechanism which is taken as too complex to be the first life form that could arise.
I'm pretty sure that many would suggest that RNA would not be the first imperfect replicator either.