This page will contain blogs about Francis Crick, as they become available.Francis CrickPhotomontage of Francis Crick lecturingProfessor Francis Harry Compton Crick, OM FRS (June 8, 1916 – July 28, 2004) was a British physicist, molecular biologist and neuroscientist, most noted for being one of the discoverers of the structure of the DNA molecule. BiographyBorn in Northampton, England as a son of Harry Crick and Annie Elisabeth Crick, he studied physics at University College London, and became a B.Sc. in 1937. During World War II, he worked on magnetic and acoustic mines. He began studying biology in 1947 after the war's end. Family and educationCrick was born and raised in the town of Northampton where Crick’s father and uncle ran the family’s shoe factory. At an early age he was attracted to science and what he could learn about it from books. As a child he was taken to church (Congregationalist) by his parents, but by about age 12 he told his mother that he no longer wanted to attend[1]. Crick preferred the scientific search for answers over belief in any traditional religious dogma. He was educated at Northampton Grammar School and, after the age of 14, Mill Hill School in London (on scholarship) where he learned mathematics, physics and chemistry. At the age of 21, Crick earned a B.Sc. degree in physics in from University College London. Crick began a Ph.D. research project in the laboratory of E. N. da C. Andrade but with the outbreak of World War II, Crick was deflected from a possible career in physics. After the war, Crick became part of an important migration of physical scientists into Biology research. This migration was made possible by the newly won influence of physicists such as John Randall who had helped win the war with inventions like radar. Crick had to adjust from the “elegance and deep simplicity” of physics to the “elaborate chemical mechanisms that natural selection had evolved over billions of years.” He described this transition as, “almost as if one had to be born again.” According to Crick, the experience of learning physics had taught him something important -hubris- and the conviction that since physics was already a success, great advances should also be possible in other sciences like biology. Crick felt that this attitude encouraged him to be more daring than typical biologists who mainly concerned themselves with the daunting problems of biology and not the past successes of physics. Biology ResearchCrick was interested in two fundamental unsolved problems of biology. First, how molecules make the transition from the non-living to the living, and second, how the brain makes mind. He realized that his background made him more qualified for research on the first topic and the field of biophysics. It was at this time of Crick’s transition from physics into biology that he was influenced by both Linus Pauling and Erwin Schroedinger. It was clear in theory that covalent bonds in biological molecules could provide the structural stability needed to hold genetic information in cells. It only remained as an exercise of experimental biology to discover exactly which molecule was the genetic molecule. In Crick’s view, Charles Darwin’s theory of evolution by natural selection, Gregor Mendel’s genetics and knowledge of the molecular basis of genetics, when combined, reveal the secret of life. It was clear that some macromolecule such as protein was likely to be the genetic molecule. However, it was well known that proteins are “doers”, macromolecules that carry out the many enzymatic reactions of cells. In the 1940’s some evidence had been found pointing to another biological molecule, DNA, the other major component of chromosomes, as a candidate genetic molecule. Oswald Avery and his collaborators showed that a phenotypic difference could be caused in bacteria by providing them with a particular DNA molecule. An X-ray diffraction image for the protein myoglobin.However, other evidence was interpreted as suggesting that DNA was structurally uninteresting and possibly just a molecular scaffold for the apparently more interesting protein molecules. Crick was in the right place, in the right frame of mind, at the right time (1949) to join Max Perutz’s project at Cambridge University, and he began to work on the X-ray crystallography of proteins. X-ray crystallography theoretically offered the opportunity to reveal the molecular structure of proteins, but there were serious technical problems then preventing X-ray crystallography from being applicable to such large molecules. X-ray crystallography 1949-1950Crick taught himself the mathematical theory of X-ray crystallography. Together with W. Cochran and V. Vand he worked out a mathematical theory of X-ray diffraction by a helical molecule. This theoretical result matched well with X-ray data obtained for proteins that contain sequences of amino acids in the Alpha helix conformation (published in Nature in 1952)[2]. During this time when Crick was learning about X-ray diffraction, researchers in the Cambridge lab were attempting to determine the most stable helical conformation of amino acid chains in proteins (the α helix). Pauling was the first to identify the 3.6 amino acids/turn ratio of the α helix. Crick was witness to the kinds of errors that his co-workers made in their failed attempts to make a correct molecular model of the α helix, these turned out to be important lessons that could be applied to the helical structure of DNA. For example, he learned the importance of the structural rigidity that double bonds confer on molecular structures which is relevant both to peptide bonds in proteins and the structure of nucleotides in DNA. Francis Crick's first sketch of the deoxyribonucleic acid double-helix patternThe Double Helix 1951-1952In 1951, he started working with James D. Watson at Cavendish Laboratory at the University of Cambridge in England. Building on the X-ray diffraction results of Maurice Wilkins, Raymond Gosling and Rosalind Franklin, they together developed the proposal of the helical structure of DNA, which they published in 1953[3], and for which they were awarded the Nobel Prize in Physiology or Medicine in 1962, together with Maurice Wilkins of University College, London[4]. When James Watson came to Cambridge, Crick was a 35 year old graduate student and Watson was only 23, but already had a Ph.D. They shared an interest in the fundamental problem of learning how genetic information might be stored in molecular form. A key piece of experimentally-derived information came from X-ray diffraction images that had been obtained by Maurice Wilkins and his student, Raymond Gosling. The images indicated to Crick, one of the few experts in helical diffraction theory, that DNA had a helical structure. Watson and Crick talked endlessly about DNA and the idea that it might be possible to guess a good molecular model of its structure. Crick and Watson produced and showed off an erroneous first model of DNA that mainly served to show how little they knew and how desperate they were to solve the structure of DNA. They knew they were competing against Pauling and feared that as for the protein α helix, Pauling would probably again win the race to discover the structure of DNA. Watson and Crick were not officially working on DNA. Crick was writing his Ph.D. thesis and Watson was supposed to be trying to obtain crystals of myoglobin for X-ray diffraction experiments. Having failed once, Watson and Crick were now somewhat reluctant (for a while Crick was ‘’forbidden’’) to make further efforts to find a molecular model of DNA. Crick described the failure of Maurice Wilkins and Rosalind Franklin to cooperate and work towards finding a molecular model as a major reason why he and Watson persisted in their efforts. Watson and Crick made use of information from unpublished X-ray diffraction images (shown at meetings, described by Wilikins, and included in administrative progress reports) to determine some basic features of the DNA helical structure such as some key dimensions and the fact that there were anti-parallel chains. Diagramatic representation of some key structural features of DNA. The similar structures of guanine:cytosine and adenine:thymine base pairs is illustrated. The base pairs are held together by hydrogen bonds. The phosphate backbones are anti-parallel.Another key to finding the correct structure of DNA was the so-called Chargaff ratios, experimentally determined ratios of the nucleotide subunits of DNA: the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. A visit by Erwin Chargaff to England in 1952 helped keep this important fact in front of Watson and Crick. The significance of these ratios for the structure of DNA were not recognized until Watson, persisting in building structural models, realized that A:T and C:G pairs are structurally similar. In particular, the length of each base pair is the same. The base pairs are held together by hydrogen bonds, the same non-covalent interaction that stabilizes the protein α helix. Watson’s recognition of the A:T and C:G pairs was aided by information from Jerry Donohue[5] about the likely structures of the nucleotides. After the discovery of the A:T and C:G pairs, Watson and Crick soon had their double helix model of DNA with the hydrogen bonds at the core of the helix providing a way to unzip the two complementary strands for easy replication: the last key requirement for a likely model of the genetic molecule. As important as Crick’s contributions to the discovery of the double helical DNA model were, he stated that without the chance to collaborate with Watson, he would not have found the structure by himself. Crick did tentatively attempt to perform some experiments on nucleotide base pairing, but he was more of a theoretical biologist than one who would perform experiments. The Watson and Crick discovery of the DNA double helix structure was made possible by their correct interpretation of the significance of experimental results that had been obtained by others. Molecular BiologyFrancis Crick also made significant contributions in laying the foundations of the now mature field of molecular biology. This includes work on the nature of the genetic code and the mechanisms of protein synthesis. After the discovery of the double helix model of DNA, Crick’s interests quickly turned to the biological implications of the structure. In 1953, Watson and Crick published another article in ‘’Nature’’ which stated: “it therefore seems likely that the precise sequence of the bases is the code that carries the genetical information”[6]. In 1953, Crick completed his Ph.D. thesis: "X-Ray Diffraction: Polypeptides and Proteins" and received his degree at the age of 37. Crick then worked in the laboratory of David Harker at Brooklyn Polytechnic Institute where he continued to develop his skills in the analysis of X-ray diffraction data for proteins, working primarily on ribonuclease. Collagen triple helix.After his short time in New York, Crick returned to Cambridge where he worked until moving to California in 1976. Crick engaged in several X-ray diffraction collaborations such as one with Alexander Rich on the structure of collagen[7]. However, Crick was quickly drifting away from continued work related to his expertise in the interpretation of X-ray diffraction patterns of proteins. George Gamow established a group of scientists who were interested in the role of RNA as an intermediary between DNA as the genetic storage molecule in the nucleus of cells and the synthesis of proteins in the cytoplasm. It was clear to Crick that there had to be a code by which a short sequence of nucleotides would specify a particular amino acid in a newly synthesized protein. In 1956 Crick wrote an informal paper about the genetic coding problem for the small group of scientists in Gamow’s RNA group[8]. In this article, Crick reviewed the evidence supporting the idea that there was a common set of about 20 amino acids used to synthesize proteins. Crick proposed that there was a corresponding set of small adaptor molecules that would hydrogen bond to short sequences of a nucleic acid and also link to one of the amino acids. He also explored the many theoretical possibilities by which short nucleic acid sequences might code for the 20 amino acids. During the mid-to-late 50s Crick was very much intellectually engaged in sorting out the mystery of how proteins are synthesized. By 1958 Crick’s thinking had matured and he could list in an orderly way all of the key features of the protein synthesis process[9].
The “adaptor molecules” were eventually shown to be tRNAs and the catalytic “ribonucleic-protein complexes” became known as ribosomes. An important step was later (1960) realization 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 4x4x4=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 oneway: 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 dominant, if not the dominant, 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[10]. 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[11]. Views on ReligionIn October 1969, Crick participated in a celebration of the 100th year of the journal Nature. Crick attempted to make some predictions about what the next 30 years would hold for molecular biology. His speculations were later published in Nature[12]. Near the end of the article, Crick briefly mentioned the search for life on other planets, but he held little hope that extraterrestrial life would be found by the year 2000. He also discussed what he described as a possible new direction for research, what he called "biochemical theology". Crick wrote, "So many people pray that one finds it hard to believe that they do not get some satisfaction from it...." Crick suggested that it might be possible to find chemical changes in the brain that were molecular correlates of the act of prayer. He speculated that there might be a detectable change in the level of some neurotransmitter or neurohormone when people pray. Crick may have been imagining substances such as dopamine that are released by the brain under certain conditions and produce rewarding sensations. Crick's suggestion that there might some day be a new science of "biochemical theology" seems to have been realized under an alternative name, there is now the new field of Neurotheology[13]. Crick's view of the realationship between science and religion would continue to play a role in his work as he made the transition from molecular biology research into theoretical neuroscience. NeuroscienceHe later left molecular biology for his other interest, consciousness. His autobiographical book What Mad Pursuit includes a description of why he left molecular biology and switched to neuroscience. Crick's book The Astonishing Hypothesis makes the argument that neuroscience now has the tools required to begin a scientific study of how brains produce conscious experiences. He was a well-known atheist who also advocated directed panspermia as a hypothesis for how life started on Earth. In 1995, Francis Crick was also one of the original endorsers of the Ashley Montagu Resolution to petition for an end to the genital mutilations of children. Starting in 1976, Crick worked at the Salk Institute in La Jolla, California. He was elected a fellow of CSICOP in 1983 and a Humanist Laureate of the International Academy of Humanism in the same year. Crick died of colon cancer at The University of California, San Diego Thornton Hospital, San Diego. Kari Olcott RN was his nurse at the time. Reactions to Crick and his WorkCrick has widely been described as talkative, brash and lacking modesty. 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 that was the center of his intellectual and professional life. Religious BeliefsAt 12, Crick decided he was an atheist[14] and spent much of the rest of his life trying to disprove the existence of the psyche. To quote political analyst Mark Steyn, "His militant atheism was good-humoured but fierce, and it drove him away from molecular biology. As the key to the mystery of life, DNA seems a small answer to the big picture, so Crick pushed on, advancing the theory of “Directed Panspermia”, which is not a Clinton DNA joke but his and his colleague Leslie Orgel’s explanation for how life began. Concerned by the narrow time frame – to those of a non-creationist bent - between the cooling of the earth and the rapid emergence of the planet’s first life forms, Crick determined to provide another explanation for the origin of life. As he put it, bouncing along a tenuous chain of probabilities: 'The first self-replicating system is believed to have arisen spontaneously in the ‘soup,’ the weak solution of organic chemicals formed in the oceans, seas, and lakes by the action of sunlight and electric storms. Exactly how it started we do not know… The universe began much earlier. Its exact age is uncertain but a figure of 10 to 15 billion years is not too far out… Although we do not know for certain, we suspect that there are in the galaxy many stars with planets suitable for life… Could life have first started much earlier on the planet of some distant star, perhaps eight to 10 billion years ago? If so, a higher civilization, similar to ours, might have developed from it at about the time that the Earth was formed… Would they have had the urge and the technology to spread life through the wastes of space and seed these sterile planets, including our own?.. For such a job, bacteria are ideal. Since they are small, many of them can be sent. They can be stored almost indefinitely at very low temperatures, and the chances are they would multiply easily in the ‘soup’ of the primitive ocean…' “We do not know… uncertain… not too far out… we do not know for certain… we suspect… chances are…” And thus the Nobel prize winner embraces the theory that space aliens sent rocketships to seed the earth. The man of science who confidently dismissed God at Mill Hill School half a century earlier appears not to have noticed that he’d merely substituted for his culturally inherited monotheism a weary variant on Graeco-Roman-Norse pantheism – the gods in the skies who fertilise the earth and then retreat to the heavens beyond our reach. To be sure, he leaves them as anonymous aliens showering seed rather than Zeus adopting the form of a swan, but nevertheless Dr Crick’s hyper-rationalism took 50 years to lead him round to embracing a belief in a celestial creator of human life, indeed a deus ex machina." Drug UseRumors have circulated that Crick told a colleague that he had taken small doses of the hallucinogenic drug LSD at the time of the discovery of the structure of DNA in order to boost his deductive powers. Crick was an outspoken advocate of Drug Reform and even founded a group called SOMA to legalize cannabis.[15] References
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Crick was an outspoken advocate of Drug Reform and even founded a group called SOMA to legalize cannabis.[15]. “We do not know… uncertain… not too far out… we do not know for certain… we suspect… chances are…” And thus the Nobel prize winner embraces the theory that space aliens sent rocketships to seed the earth. Scientists determined the levels of arsenic from hair and nail samples. They can be stored almost indefinitely at very low temperatures, and the chances are they would multiply easily in the ‘soup’ of the primitive ocean…'. However critics point out the cause of death remains unknown, despite frequent reporting in the media otherwise. Since they are small, many of them can be sent. It is widely held that the cause of Taylor's death was put to rest in the early 1990s when Taylor's remains were exhumed and examined [1] for arsenic poisoning. For such a job, bacteria are ideal. Taylor was succeeded by his vice president, Millard Fillmore. Could life have first started much earlier on the planet of some distant star, perhaps eight to 10 billion years ago? If so, a higher civilization, similar to ours, might have developed from it at about the time that the Earth was formed… Would they have had the urge and the technology to spread life through the wastes of space and seed these sterile planets, including our own?.. He is buried in Louisville, Kentucky in the Zachary Taylor National Cemetery. Although we do not know for certain, we suspect that there are in the galaxy many stars with planets suitable for life…. He died five days later, after just 16 months in office. Its exact age is uncertain but a figure of 10 to 15 billion years is not too far out…. After participating in ceremonies at the Washington Monument on a blistering July 4, 1850, Taylor fell ill with acute indigestion and was diagnosed by his physicians with cholera morbus. The universe began much earlier. with less reluctance than he had hanged deserters and spies in Mexico." He never wavered. Exactly how it started we do not know…. Persons "taken in rebellion against the Union, he would hang .. As he put it, bouncing along a tenuous chain of probabilities: 'The first self-replicating system is believed to have arisen spontaneously in the ‘soup,’ the weak solution of organic chemicals formed in the oceans, seas, and lakes by the action of sunlight and electric storms. He told them that if necessary to enforce the laws, he personally would lead the Army. Concerned by the narrow time frame – to those of a non-creationist bent - between the cooling of the earth and the rapid emergence of the planet’s first life forms, Crick determined to provide another explanation for the origin of life. In February 1850 President Taylor had held a stormy conference with southern leaders who threatened secession. As the key to the mystery of life, DNA seems a small answer to the big picture, so Crick pushed on, advancing the theory of “Directed Panspermia”, which is not a Clinton DNA joke but his and his colleague Leslie Orgel’s explanation for how life began. In addition, Taylor's solution ignored several acute side issues: the northern dislike of the slave market operating in the District of Columbia and the southern demands for a more stringent fugitive slave law. To quote political analyst Mark Steyn, "His militant atheism was good-humoured but fierce, and it drove him away from molecular biology. Southerners were furious, since neither state constitution was likely to permit slavery; members of Congress were dismayed, since they felt the President was usurping their policy-making prerogatives. At 12, Crick decided he was an atheist[14] and spent much of the rest of his life trying to disprove the existence of the psyche. Therefore, to end the dispute over slavery in new areas, Taylor urged settlers in New Mexico and California to draft constitutions and apply for statehood, bypassing the territorial stage. 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 that was the center of his intellectual and professional life. Traditionally, people could decide whether they wanted slavery when they drew up new state constitutions. Crick has widely been described as talkative, brash and lacking modesty. Under Taylor´s administration the United States Department of the Interior was organized, although the Department had been activated under President Polk´s last day in office. Kari Olcott RN was his nurse at the time. As disheveled as always, Taylor tried to run his administration in the same rule-of-thumb fashion with which he had fought Indians. Crick died of colon cancer at The University of California, San Diego Thornton Hospital, San Diego. He acted at times as though he were above parties and politics. He was elected a fellow of CSICOP in 1983 and a Humanist Laureate of the International Academy of Humanism in the same year. Although Taylor had subscribed to Whig principles of legislative leadership, he was not inclined to be a puppet of Whig leaders in Congress. Starting in 1976, Crick worked at the Salk Institute in La Jolla, California. Constitutionally, Taylor's term began at noon on March 4, regardless of whether he had taken the oath or not. In 1995, Francis Crick was also one of the original endorsers of the Ashley Montagu Resolution to petition for an end to the genital mutilations of children. Some people postulate that David Rice Atchison, the previous President Pro Tempore of the Senate, was technically Acting President, but this statement is rejected by virtually every constitutional scholar. He was a well-known atheist who also advocated directed panspermia as a hypothesis for how life started on Earth. As a result, it is claimed that the nation technically had no President or Vice President for one day. Crick's book The Astonishing Hypothesis makes the argument that neuroscience now has the tools required to begin a scientific study of how brains produce conscious experiences. Vice President Millard Fillmore was also not sworn in on that day. His autobiographical book What Mad Pursuit includes a description of why he left molecular biology and switched to neuroscience. His term of service was scheduled to begin at noon on March 4, 1849, but it being a Sunday, Taylor refused to be sworn in until the following day. He later left molecular biology for his other interest, consciousness. Taylor earned a footnote in Presidential history before he even took office. Crick's view of the realationship between science and religion would continue to play a role in his work as he made the transition from molecular biology research into theoretical neuroscience. In a close election, the Free Soilers pulled enough votes away from Cass to elect Taylor. Crick's suggestion that there might some day be a new science of "biochemical theology" seems to have been realized under an alternative name, there is now the new field of Neurotheology[13]. In protest against Taylor, a slaveholder, and Cass, an advocate of "squatter sovereignty," northerners who opposed extension of slavery into territories, formed the Free Soil Party and nominated Martin Van Buren. Crick may have been imagining substances such as dopamine that are released by the brain under certain conditions and produce rewarding sensations. He ran against the Democratic candidate, Lewis Cass, who favored letting the residents of territories decide for themselves whether they wanted slavery. He speculated that there might be a detectable change in the level of some neurotransmitter or neurohormone when people pray. He also had not previously committed himself on troublesome issues. Crick suggested that it might be possible to find chemical changes in the brain that were molecular correlates of the act of prayer. His homespun ways were political assets, his long military record would appeal to northerners, and his ownership of slaves would attract southern votes. Crick wrote, "So many people pray that one finds it hard to believe that they do not get some satisfaction from it....". In fact, he had never even bothered to register, and didn't vote in his own election. He also discussed what he described as a possible new direction for research, what he called "biochemical theology". He received the Whig nomination for President in 1848, although he had never even bothered to vote before. Near the end of the article, Crick briefly mentioned the search for life on other planets, but he held little hope that extraterrestrial life would be found by the year 2000. Taylor, incensed, thought that "the battle of Buena Vista opened the road to the city of Mexico and the halls of Montezuma, that others might revel in them.". His speculations were later published in Nature[12]. He sent an expedition under General Winfield Scott to capture Mexico City. Crick attempted to make some predictions about what the next 30 years would hold for molecular biology. Polk kept Taylor in northern Mexico, disturbed by his informal habits of command and his affiliation with the Whig Party. In October 1969, Crick participated in a celebration of the 100th year of the journal Nature. Polk later declared war; in the Mexican-American War that followed, Taylor won additional important victories at Monterrey and Buena Vista and became a national hero. 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[11]. When the Mexicans attacked Taylor's troops, Taylor defeated them despite being outnumbered 4-to-1. Proof that the genetic code is a degenerate triplet code finally came from genetics experiments, some of which were performed by Crick[10]. Polk sent an army under his command to the Rio Grande in 1846. Crick had by this time become a dominant, if not the dominant, theoretical molecular biologist. President James K. Crick was focused on this third component (information) and it became the organizing principle of what became known as molecular biology. During the Seminole War he gained the nickname "Old Rough and Ready" after the Battle of Lake Okeechobee. 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. Taylor also served in the Black Hawk War (1832) and the Second Seminole War (1835–1842). 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. It is believed that Taylor sometimes needed to be boosted into his saddle. Crick also used the term “central dogma” to summarize an idea that implies that genetic information flow between macromolecules would be essentially oneway: Crick also explored other codes in which for various reasons only some of the triplets were used, “magically” producing just the 20 needed combinations. Soon afterward he was ordered west into Indiana Territory, taking command of Fort Harrison. Some amino acids might have multiple triplet codes. Army and was commissioned as a first lieutenant. Such a code might be “degenerate”, with 4x4x4=64 possible triplets of the four nucleotide subunits while there were only 20 amino acids. In 1808, Taylor joined the U.S. In his 1958 article, Crick speculated, as had others, that a triplet of nucleotides could code for an amino acid. They had one son and five daughters, two of whom died in infancy. None of this, however, answered the fundamental theoretical question of the exact nature of the genetic code. As an infant he and his family moved to Kentucky, where Taylor grew up on a plantation and was known as "Little Zack." Taylor and Margaret Mackall Smith met in early 1810 and were married on June 21, 1812. An important step was later (1960) realization that the messenger RNA was not the same as the ribosomal RNA. Taylor was born in a log cabin to Richard Taylor and Sarah Strother, near Barboursville, Virginia, though his family was aristocratic. The “adaptor molecules” were eventually shown to be tRNAs and the catalytic “ribonucleic-protein complexes” became known as ribosomes. . By 1958 Crick’s thinking had matured and he could list in an orderly way all of the key features of the protein synthesis process[9]. He was the second president to die in office. During the mid-to-late 50s Crick was very much intellectually engaged in sorting out the mystery of how proteins are synthesized. Taylor was noted for his extensive military career, becoming the first president not previously elected to any other public office. He also explored the many theoretical possibilities by which short nucleic acid sequences might code for the 20 amino acids. Zachary Taylor (November 24, 1784 – July 9, 1850), also known as "Old Rough and Ready," was the twelfth President of the United States, serving from 1849 to 1850. Crick proposed that there was a corresponding set of small adaptor molecules that would hydrogen bond to short sequences of a nucleic acid and also link to one of the amino acids. In this article, Crick reviewed the evidence supporting the idea that there was a common set of about 20 amino acids used to synthesize proteins. In 1956 Crick wrote an informal paper about the genetic coding problem for the small group of scientists in Gamow’s RNA group[8]. It was clear to Crick that there had to be a code by which a short sequence of nucleotides would specify a particular amino acid in a newly synthesized protein. George Gamow established a group of scientists who were interested in the role of RNA as an intermediary between DNA as the genetic storage molecule in the nucleus of cells and the synthesis of proteins in the cytoplasm. However, Crick was quickly drifting away from continued work related to his expertise in the interpretation of X-ray diffraction patterns of proteins. Crick engaged in several X-ray diffraction collaborations such as one with Alexander Rich on the structure of collagen[7]. After his short time in New York, Crick returned to Cambridge where he worked until moving to California in 1976. Crick then worked in the laboratory of David Harker at Brooklyn Polytechnic Institute where he continued to develop his skills in the analysis of X-ray diffraction data for proteins, working primarily on ribonuclease. thesis: "X-Ray Diffraction: Polypeptides and Proteins" and received his degree at the age of 37. In 1953, Crick completed his Ph.D. In 1953, Watson and Crick published another article in ‘’Nature’’ which stated: “it therefore seems likely that the precise sequence of the bases is the code that carries the genetical information”[6]. After the discovery of the double helix model of DNA, Crick’s interests quickly turned to the biological implications of the structure. This includes work on the nature of the genetic code and the mechanisms of protein synthesis. Francis Crick also made significant contributions in laying the foundations of the now mature field of molecular biology. The Watson and Crick discovery of the DNA double helix structure was made possible by their correct interpretation of the significance of experimental results that had been obtained by others. Crick did tentatively attempt to perform some experiments on nucleotide base pairing, but he was more of a theoretical biologist than one who would perform experiments. As important as Crick’s contributions to the discovery of the double helical DNA model were, he stated that without the chance to collaborate with Watson, he would not have found the structure by himself. After the discovery of the A:T and C:G pairs, Watson and Crick soon had their double helix model of DNA with the hydrogen bonds at the core of the helix providing a way to unzip the two complementary strands for easy replication: the last key requirement for a likely model of the genetic molecule. Watson’s recognition of the A:T and C:G pairs was aided by information from Jerry Donohue[5] about the likely structures of the nucleotides. The base pairs are held together by hydrogen bonds, the same non-covalent interaction that stabilizes the protein α helix. In particular, the length of each base pair is the same. The significance of these ratios for the structure of DNA were not recognized until Watson, persisting in building structural models, realized that A:T and C:G pairs are structurally similar. A visit by Erwin Chargaff to England in 1952 helped keep this important fact in front of Watson and Crick. Another key to finding the correct structure of DNA was the so-called Chargaff ratios, experimentally determined ratios of the nucleotide subunits of DNA: the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine. Watson and Crick made use of information from unpublished X-ray diffraction images (shown at meetings, described by Wilikins, and included in administrative progress reports) to determine some basic features of the DNA helical structure such as some key dimensions and the fact that there were anti-parallel chains. Crick described the failure of Maurice Wilkins and Rosalind Franklin to cooperate and work towards finding a molecular model as a major reason why he and Watson persisted in their efforts. Having failed once, Watson and Crick were now somewhat reluctant (for a while Crick was ‘’forbidden’’) to make further efforts to find a molecular model of DNA. thesis and Watson was supposed to be trying to obtain crystals of myoglobin for X-ray diffraction experiments. Crick was writing his Ph.D. Watson and Crick were not officially working on DNA. They knew they were competing against Pauling and feared that as for the protein α helix, Pauling would probably again win the race to discover the structure of DNA. Crick and Watson produced and showed off an erroneous first model of DNA that mainly served to show how little they knew and how desperate they were to solve the structure of DNA. Watson and Crick talked endlessly about DNA and the idea that it might be possible to guess a good molecular model of its structure. The images indicated to Crick, one of the few experts in helical diffraction theory, that DNA had a helical structure. A key piece of experimentally-derived information came from X-ray diffraction images that had been obtained by Maurice Wilkins and his student, Raymond Gosling. They shared an interest in the fundamental problem of learning how genetic information might be stored in molecular form. When James Watson came to Cambridge, Crick was a 35 year old graduate student and Watson was only 23, but already had a Ph.D. Building on the X-ray diffraction results of Maurice Wilkins, Raymond Gosling and Rosalind Franklin, they together developed the proposal of the helical structure of DNA, which they published in 1953[3], and for which they were awarded the Nobel Prize in Physiology or Medicine in 1962, together with Maurice Wilkins of University College, London[4]. Watson at Cavendish Laboratory at the University of Cambridge in England. In 1951, he started working with James D. For example, he learned the importance of the structural rigidity that double bonds confer on molecular structures which is relevant both to peptide bonds in proteins and the structure of nucleotides in DNA. Crick was witness to the kinds of errors that his co-workers made in their failed attempts to make a correct molecular model of the α helix, these turned out to be important lessons that could be applied to the helical structure of DNA. Pauling was the first to identify the 3.6 amino acids/turn ratio of the α helix. During this time when Crick was learning about X-ray diffraction, researchers in the Cambridge lab were attempting to determine the most stable helical conformation of amino acid chains in proteins (the α helix). This theoretical result matched well with X-ray data obtained for proteins that contain sequences of amino acids in the Alpha helix conformation (published in Nature in 1952)[2]. Vand he worked out a mathematical theory of X-ray diffraction by a helical molecule. Cochran and V. Together with W. Crick taught himself the mathematical theory of X-ray crystallography. X-ray crystallography theoretically offered the opportunity to reveal the molecular structure of proteins, but there were serious technical problems then preventing X-ray crystallography from being applicable to such large molecules. Crick was in the right place, in the right frame of mind, at the right time (1949) to join Max Perutz’s project at Cambridge University, and he began to work on the X-ray crystallography of proteins. However, other evidence was interpreted as suggesting that DNA was structurally uninteresting and possibly just a molecular scaffold for the apparently more interesting protein molecules. Oswald Avery and his collaborators showed that a phenotypic difference could be caused in bacteria by providing them with a particular DNA molecule. In the 1940’s some evidence had been found pointing to another biological molecule, DNA, the other major component of chromosomes, as a candidate genetic molecule. However, it was well known that proteins are “doers”, macromolecules that carry out the many enzymatic reactions of cells. It was clear that some macromolecule such as protein was likely to be the genetic molecule. In Crick’s view, Charles Darwin’s theory of evolution by natural selection, Gregor Mendel’s genetics and knowledge of the molecular basis of genetics, when combined, reveal the secret of life. It only remained as an exercise of experimental biology to discover exactly which molecule was the genetic molecule. It was clear in theory that covalent bonds in biological molecules could provide the structural stability needed to hold genetic information in cells. It was at this time of Crick’s transition from physics into biology that he was influenced by both Linus Pauling and Erwin Schroedinger. He realized that his background made him more qualified for research on the first topic and the field of biophysics. First, how molecules make the transition from the non-living to the living, and second, how the brain makes mind. Crick was interested in two fundamental unsolved problems of biology. Crick felt that this attitude encouraged him to be more daring than typical biologists who mainly concerned themselves with the daunting problems of biology and not the past successes of physics. Crick had to adjust from the “elegance and deep simplicity” of physics to the “elaborate chemical mechanisms that natural selection had evolved over billions of years.” He described this transition as, “almost as if one had to be born again.” According to Crick, the experience of learning physics had taught him something important -hubris- and the conviction that since physics was already a success, great advances should also be possible in other sciences like biology. This migration was made possible by the newly won influence of physicists such as John Randall who had helped win the war with inventions like radar. After the war, Crick became part of an important migration of physical scientists into Biology research. Andrade but with the outbreak of World War II, Crick was deflected from a possible career in physics. da C. N. research project in the laboratory of E. Crick began a Ph.D. degree in physics in from University College London. At the age of 21, Crick earned a B.Sc. He was educated at Northampton Grammar School and, after the age of 14, Mill Hill School in London (on scholarship) where he learned mathematics, physics and chemistry. Crick preferred the scientific search for answers over belief in any traditional religious dogma. As a child he was taken to church (Congregationalist) by his parents, but by about age 12 he told his mother that he no longer wanted to attend[1]. At an early age he was attracted to science and what he could learn about it from books. Crick was born and raised in the town of Northampton where Crick’s father and uncle ran the family’s shoe factory. He began studying biology in 1947 after the war's end. During World War II, he worked on magnetic and acoustic mines. in 1937. Born in Northampton, England as a son of Harry Crick and Annie Elisabeth Crick, he studied physics at University College London, and became a B.Sc. . Professor Francis Harry Compton Crick, OM FRS (June 8, 1916 – July 28, 2004) was a British physicist, molecular biologist and neuroscientist, most noted for being one of the discoverers of the structure of the DNA molecule. Watson (Mitchell Lane Publishers, Inc., 2002) ISBN 1584151226. Francis Crick and James Watson: Pioneers in DNA Research by John Bankston, Francis Crick and James D. The book also formed the basis of the award winning television dramatisation Life Story by BBC Horizon (also broadcast as Race for the Double Helix). Watson, The Double Helix: A Personal Account of the Discovery of the Structure of DNA, Atheneum, 1980, ISBN 0689706022 (first published in 1968) is a very readable first hand account of the research by Crick and Watson. James D. Edward Edelson, Francis Crick And James Watson: And the Building Blocks of Life Oxford University Press, 2000, ISBN 0195139712. The Astonishing Hypothesis: The Scientific Search For The Soul (Scribner reprint edition, 1995) ISBN 0684801582. Of Molecules and Men (Prometheus Books, 2004; original edition 1967) ISBN 1591021855. Life Itself (Simon & Schuster, 1981) ISBN 0671255622. ^ Online at hallucinogens.com: Nobel Prize genius Crick was high on LSD when he discovered the secret of life by Alun Rees. Crick's description of his religious views (as given in What Mad Pursuit, see Chapter 1 of reference #1, above) after having told his mother that he no longer wished to attend church services: "...from then on I was a skeptic, an agnostic with a strong inclination toward atheism.". ^ See The Twentieth-Century Darwin by Mark Steyn published in The Atlantic Monthly October 2004. Entrez PubMed 14594742. Farde in The American Journal of Psychiatry (2003) Volume 160, pages 1965-1969. Soderstrom and L. Andree, H. Borg, B. ^ "The serotonin system and spiritual experiences" by J. ^ "Molecular Biology in the Year 2000" by Francis Crick in Nature Volume 228 (1970) pages 613-615. Crick in Proc R Soc Lond B Biol Sci. (1967) Volume 167 pages 331-347. H. The genetic code" by F. ^ "The Croonian lecture, 1966. Watts-Tobin in Nature (1961) Volume 192 pages 1227-1232. J. Brenner and R. Barnett, S. Crick, L. H. ^ "General nature of the genetic code for proteins" by F. Crick in Symp Soc Exp Biol. (1958);12:138-63. H. ^ "On protein synthesis" by F. ^ "On Degenerate Templates and the Adaptor Hypothesis: A Note for the RNA Tie Club" by Francis Crick (1956). Crick in Nature (1955) Volume 176, pages 915-916. H. ^ "The structure of collagen" by A Rich and F. Crick (1953) in Nature Volume 171 pages 964-967. H. Watson and F. D. ^ "Genetical implications of the structure of deoxyribonucleic acid" by J. ^ See Chapter 3 of The Eighth Day of Creation: Makers of the Revolution in Biology by Horace Freeland Judson published by Cold Spring Harbor Laboratory Press (1996) ISBN 0879694785. ^ Francis Crick's 1962 Biography from the Nobel foundation. Nature 171, 737–738 (1953). Crick. Watson and Francis H. ^ Molecular structure of Nucleic Acids by James D. Crick's scientific publications and letters are in the list of Francis Crick's Papers from the Wellcome Library at the National Library of Medicine. ^ See "Evidence for the Pauling-Corey alpha-Helix in Synthetic Polypeptides" (1952) Nature Volume 169 pages 234-235 (download PDF). ^ Chapters 1 and 2 of What Mad Pursuit: A Personal View of Scientific Discovery by Francis Crick (Basic Books reprint edition, 1990 ISBN 0465091385) provide Crick's description of his early life and education. ribonucleic-protein complexes that catalyze the assembly of amino acids into proteins according to the messenger RNA. adaptor molecules (“they might contain nucleotides”) to match short sequences of nucleotides in the RNA messenger molecules to specific amino acids. a “messenger” RNA molecule to carry the instructions for making one protein to the cytoplasm. genetic information stored in the sequence of DNA molecules. |