He has been described as 'the Charles Darwin of the 20th century' by Professor Steve Jones of University College London and as 'the dominant hero of the heroic age of molecular biology' by Professor Richard Dawkins of Oxford University. He was a Nobel Prize winner, a Fellow of the Royal Society and was appointed to the Order of Merit. Sadly, on Wednesday 28th July at the age of 88, Francis Crick died of colon cancer, in a hospital near his home in San Diego, US.

Crick helped answer three of the greatest questions of biology: the structure of DNA; the way in which DNA stores information; and the way the information encoded in DNA is used. It was in partnership with James Watson at Cavendish College, Cambridge, in 1953 that Crick made the first of these discoveries. Using data from research carried out by Maurice Wilkins and Rosalind Franklin and a hefty dose of imagination, Crick and Watson worked out the structure of DNA: the double helix.

The double helix immediately suggested a way in which information was stored, in the sequence of DNA bases, and a mechanism by which the information could be passed on. Crick famously wrote, 'it has not escaped our notice that the specific pairing that we have postulated immediately suggests a possible copying mechanism for the genetic material'. For this discovery, Crick, Watson and Wilkins received the Nobel Prize for Medicine 1962; Franklin, however, had died four years previously.

Crick's work did not end there. He and Sydney Brenner cracked the DNA code, working out the sequences of DNA bases that correspond to the amino acids used to make protein. Later he moves to San Diego, taking up a position at the Salk Institute, studying consciousness. He wrote a book, The Astonishing Hypothesis, explaining his theory on consciousness: that it is solely the product of cells in the brain.

Watson, who remained friends with Crick after their productive partnership in the 1950s, said in tribute, 'I will always remember Francis for his extraordinarily focused intelligence and for the many ways he showed me kindness'.