Alexander (Alec) Rawson Stokes (27 June 1919, Macclesfield – 5 February 2003) was a co-author of one1 of the three papers published sequentially in Nature in March 19532 announcing the presumed molecular structure of DNA. The first was authored by Francis Crick and James Watson,3 and the third by Rosalind Franklin and Raymond Gosling.4 The Nobel Prize in Medicine was awarded in 1962 to Crick, Watson and Wilkins for this work. In 1993, on the 40th anniversary of the publication of the molecular structure of DNA, a plaque was erected in the Quad (courtyard) of the Strand campus of King's College London commemorating the contributions of Franklin, Gosling, Stokes, Wilson and Wilkins to DNA X-ray diffraction studies.
He received a first-class degree in the natural science tripos in 1940 at Trinity College Cambridge and then researched X-ray crystallography of Imperfect Crystals for his PhD in 1943 under the supervision of Lawrence Bragg at the Cavendish Laboratory. Stokes lectured in physics at Royal Holloway College, London before joining John Randall's Biophysics Research Unit at King's College London in 1947. He has been credited5 as being the first person to demonstrate that the DNA molecule was probably helical in shape. Maurice Wilkins wrote in his autobiography (page 160) 6 that he asked Stokes to predict what a helical structure would look like as an x-ray diffraction photograph, and that he was able to determine this by the next day through mathematical calculations made during a short train journey. Stokes continued to work on optical diffraction in large biological molecules. His publications include the books The Theory of the Optical Properties of Inhomogeneous Materials. London: E. and F.N. Spon Ltd, (1963) and The Principles of Atomic and Nuclear Physics C.J. Smith and A.R. Stokes, London, Edward Arnold, (1972) ISBN 0-7131-2313-3.7
^"Molecular Structure of Deoxypentose Nucleic Acids." by M H F Wilkins, A R Stokes and H R Wilson in Nature (1953) volume, 171 pages 738-740. monograph: 
Chomet, S. (Ed.), D.N.A. Genesis of a Discovery, 1994, Newman- Hemisphere Press, London; NB a few copies are available from Newman-Hemisphere at 101 Swan Court, London SW3 5RY (phone: 07092 060530).
Wilkins, Maurice, The Third Man of the Double Helix: The Autobiography of Maurice Wilkins ISBN 0-19-860665-6.
Ridley, Matt; "Francis Crick: Discoverer of the Genetic Code (Eminent Lives)" was first published in June 2006 in the USA and will be then in the UK September 2006, by HarperCollins Publishers; 192 pp, ISBN 0-06-082333-X. This short book is in the publisher's Eminent Lives" series.
Tait, Sylvia & James "A Quartet of Unlikely Discoveries" (Athena Press 2004) ISBN 1-84401-343-X.