Whilst watching the rather excellent X-Men I was minded of the fact that this week is the fiftieth anniversary of the discovery of DNA. Well discovery is not quite right, DNA had been know about for sometime but what Francis Crick and James Watson did was much more significant, they deciphered the complicated double helix structure. And so significant was Watson and Cricks work that Nobel Laureate Peter Medawar believes, 'It is simply not worth arguing with anyone so obtuse as not to realise that this complex of discoveries is the greatest achievements of science in the twentieth century'. I am inclined to agree with him.