Francis Crick : biography
The adaptor molecules were eventually shown to be tRNAs and the catalytic "ribonucleic-protein complexes" became known as ribosomes. An important step was later realization (in 1960) that the messenger RNA was not the same as the ribosomal RNA. None of this, however, answered the fundamental theoretical question of the exact nature of the genetic code. In his 1958 article, Crick speculated, as had others, that a triplet of nucleotides could code for an amino acid. Such a code might be "degenerate", with 4×4×4=64 possible triplets of the four nucleotide subunits while there were only 20 amino acids. Some amino acids might have multiple triplet codes. Crick also explored other codes in which, for various reasons, only some of the triplets were used, "magically" producing just the 20 needed combinations. Experimental results were needed; theory alone could not decide the nature of the code. Crick also used the term "central dogma" to summarize an idea that implies that genetic information flow between macromolecules would be essentially one-way:
- DNA → RNA → Protein
Some critics thought that by using the word "dogma", Crick was implying that this was a rule that could not be questioned, but all he really meant was that it was a compelling idea without much solid evidence to support it. In his thinking about the biological processes linking DNA genes to proteins, Crick made explicit the distinction between the materials involved, the energy required, and the information flow. Crick was focused on this third component (information) and it became the organizing principle of what became known as molecular biology. Crick had by this time become a highly influential theoretical molecular biologist.
Proof that the genetic code is a degenerate triplet code finally came from genetics experiments, some of which were performed by Crick. The details of the code came mostly from work by Marshall Nirenberg and others who synthesized synthetic RNA molecules and used them as templates for in vitro protein synthesis.
Crick died of colon cancer on 28 July 2004 at the University of California San Diego (UCSD) Thornton Hospital in La Jolla; he was cremated and his ashes were scattered into the Pacific Ocean. A public memorial was held on 27 September 2004 at the Salk Institute, La Jolla, near San Diego, California; guest speakers included James D. Watson, Sydney Brenner, Alex Rich, Seymour Benzer, Aaron Klug, Christof Koch, Pat Churchland, Vilayanur Ramachandran, Tomaso Poggio, Leslie Orgel, Terry Sejnowski, his son Michael Crick, and his youngest daughter Jacqueline Nichols. A private memorial for family and colleagues was held on 3 August 2004.
Crick was often described as very talkative, with Watson – in The Double Helix – implying lack of modesty.Watson’s book The Double Helix painted a vivid image of Crick, starting with the famous line, "I have never seen Francis Crick in a modest mood." The first chapter of Horace Judson’s book The Eighth Day of Creation describes the importance of Crick’s talking and his boldness in his scientific style. His personality combined with his scientific accomplishments produced many opportunities for Crick to stimulate reactions from others, both inside and outside of the scientific world, which was the centre of his intellectual and professional life.Describing Crick’s influence on his scientific colleagues, Francis Crick Papers archivist Chris Beckett wrote of the importance of, "…..Crick’s presence and eloquence —direct and beguiling, by all accounts in the archive— at conference after conference, through formal lectures, extempore summaries, informal meetings and individual conversations. Indeed, one has the impression that it was through these frequent persuasive moments of personal delivery and purposive conversations that Crick was most influential.". Also described as an example of Crick’s wide recognition and public profile are some of the times Crick was addressed as "Sir Francis Crick" with the assumption that someone so famous must have been knighted. Crick spoke rapidly, and rather loudly, and had an infectious and reverberating laugh, and a lively sense of humour. One colleague from the Salk Institute described him as "a brainstorming intellectual powerhouse with a mischievous smile…. Francis was never mean-spirited, just incisive. He detected microscopic flaws in logic. In a room full of smart scientists, Francis continually reearned his position as the heavyweight champ."Eagleman, D.M. (2005). Vision Research. 45: 391-393.