Double helix

It's good to be reminded every now and then of the depth and beauty of the revolution in understanding that Watson and Crick facilitated in 1953:

A vital gene that defends us against cancer has been found in one of the simplest of [multicellular] animals – a...placozoan. The discovery shows that p53, sometimes described as the "guardian of the genome", has been around for over 1 billion years...Human p53 is a closer match to the placozoan version than it is to counterparts in more closely related animals such as flies and worms.

-- from DNA's guardian gene found in placazoans