Bansal’s paper clearly illustrates some of the troubling issues pertaining to Crick and Watson’s helical structure. It should be remembered that originally there were just two forms of DNA... A (dehydrated) and B (hydrated). It was only with the onset of synthesis in the 1970’s that the multitudinous alternate structures began to be appear - C,D,T,Z etc. Whilst many of these variations would support C/W’s pairing, it should be pointed out that if you propose, design and build a structure incorrectly, the imaging of such structures will merely confirm what you have built. This can in no way be used to prove that natural DNA given free choice would form in the way that these structures have done. Whilst it may be possible to synthesize almost any structure - modern plastics being an obvious example - it does not necessarily follow that they would occur within the natural scheme of nature.
