I do think we need to tighten up our thinking about DNA (see lecture title). Crick did not discover DNA. As I recall it was Miescher who first identified DNA. Crick postulated a structure for DNA. He & Watson did not invent plectonemic winding in DNA and did not invent the idea of the complementarity of strands.Moreover there is now a substantial body of evidence that duplex DNA is anyway a paranemic structure and the evidence for this has been fully set down, starting in 1991, again in 1997 and again in 2003 (www.notahelix.com/delmonte/index_delmonte.htm). This work has been referred to by J C Wang in his recent book and was known to Crick in 1991 when he received a copy of the book "Towards a New Structural Molecular Biology." The work was also referred to in a letter from Nobel Laureate Aaron Klug to Crick in 1991 and recorded in the Crick archive in London maintained by the Wellcome Foundation.