John Burdon Sanderson Haldane FRS (November 5, 1892 – December 1, 1964), known as Jack (but who used 'J.B.S.' in his printed works), was a British geneticist and evolutionary biologist. He was one of the founders (along with Ronald Fisher and Sewall Wright) of population genetics.

Haldane was born in Edinburgh, to physiologist John Scott Haldane and Louisa Kathleen Haldane (née Trotter), and descended from Scottish aristocrats (see Haldane family). His younger sister Naomi Mitchison became a writer. His uncle was Richard Haldane, 1st Viscount Haldane, politician and one time Secretary of State for War and his aunt was the author Elizabeth Haldane.

Haldane was educated at Dragon School, then at Eton (where he spent six years and suffered a certain amount of bullying at first, but ended up being Captain of the School) and at New College, Oxford, where he graduated in 1911.

In January 1915, Haldane entered the First World War in France, serving with the Black Watch in France and Iraq. He was initially Bombing Officer for the 3rd Battalion before becoming a Trench Mortar Officer in the 1st. He took to the task of Bombing Officer with such enthusiasm that he was nicknamed Bombo. While in the army, he became a socialist, writing "If I live to see an England in which socialism has made the occupation of a grocer as honourable as that of a soldier, I shall die happy". He completed his war service in January 1919.

Between 1919 and 1922 he was a Fellow of New College, Oxford, then moved to Cambridge University, where he accepted a Readership in Biochemistry at Trinity College and taught there until 1932. During his nine years at Cambridge, Haldane worked on enzymes and genetics, particularly the mathematical side of genetics. During the teens and twenties, Haldane wrote many popular essays on science that were eventually collected and published in 1927 in a volume entitled Possible Worlds.

He then accepted a position as Professor of Genetics and moved to University College London where he spent most of his academic career. Four years later he became the first Weldon Professor of Biometry at University College London. In the late 1950s he moved to India at the invitation of P.C. Mahalanobis. The move was ostensibly a protest against the Suez War, but had been a possibility for some while; he was in any case facing retirement from UCL. He became an Indian citizen.

In 1923 in a talk given in Cambridge, Haldane, foreseeing the exhaustion of coal for power generation in Britain, proposed a network of hydrogen-generating windmills. This is the first proposal of the hydrogen-based renewable energy economy.

In 1924 Haldane met Charlotte Burghes (nee Franken), a young reporter for the Daily Express, and the two later married. To do so Charlotte divorced her husband Jack Burghes, causing some controversy. Haldane was almost dismissed from Cambridge for the way he handled his meeting with her, which led to the divorce.

In 1925, GE Briggs and Haldane derived a new interpretation of the enzyme kinetics law described by Victor Henri in 1903, different from the 1913 Michaelis-Menten equation. Leonor Michaelis and Maud Menten assumed that enzyme (catalyst) and substrate (reactant) are in fast equilibrium with their complex, which then dissociates to yield product and free enzyme. The Briggs-Haldane equation was of the same algebraic form, but their derivation is based on the quasi steady state approximation, that is the concentration(s) of intermediate complex(es) do(es) not change. As a result, the microscopic meaning of the "Michaelis Constant" (km) is different. Although commonly referring it as Michaelis-Menten kinetics, most of the current models actually use the Briggs-Haldane derivation.

Haldane made many contributions to human genetics and was one of the three major figures to develop the mathematical theory of population genetics. He is usually regarded as the third of these in importance, after R. A. Fisher and Sewall Wright. His greatest contribution was in a series of ten papers on "A Mathematical Theory of Natural and Artificial Selection" which was the major series of papers on the mathematical theory of natural selection. It treated many major cases for the first time, showing the direction and rates of changes of gene frequencies. It also pioneered in investigating the interaction of natural selection with mutation and with migration. Haldane's book, The Causes of Evolution (1932), summarized these results, especially in its extensive appendix. This body of work was a component of what came to be known as the "modern evolutionary synthesis", reestablishing natural selection as the premier mechanism of evolution by explaining it in terms of the mathematical consequences of Mendelian genetics.

Haldane introduced many quantitative approaches in biology such as in his essay On Being the Right Size. His contributions to theoretical population genetics and statistical human genetics included the first methods using maximum likelihood for estimation of human linkage maps, and pioneering methods for estimating human mutation rates. His was the first to calculate the mutational load caused by recurring mutations at a gene locus, and to introduce the idea of a "cost of natural selection".

Haldane is also known for an observation from his essay, On Being the Right Size, which Jane Jacobs and others have since referred to as Haldane's principle. This is that sheer size very often defines what bodily equipment an animal must have: "Insects, being so small, do not have oxygen-carrying bloodstreams. What little oxygen their cells require can be absorbed by simple diffusion of air through their bodies. But being larger means an animal must take on complicated oxygen pumping and distributing systems to reach all the cells." The conceptual metaphor to animal body complexity has been of use in energy economics and secession ideas.

Haldane was a keen experimenter, willing to expose himself to danger to obtain data. One experiment involving elevated levels of oxygen saturation triggered a fit which resulted in him suffering crushed vertebrae. In his decompression chamber experiments, he and his volunteers suffered perforated eardrums, but, as Haldane stated in What is Life, "the drum generally heals up; and if a hole remains in it, although one is somewhat deaf, one can blow tobacco smoke out of the ear in question, which is a social accomplishment."

He was also a famous science populariser like Isaac Asimov, Stephen Jay Gould, or Richard Dawkins. His essay, 'Daedalus; or, Science and the Future' (1923), was remarkable in predicting many scientific advances but has been criticized for presenting a too idealistic view of scientific progress.

Haldane was very idealistic, and in his youth was a devoted Communist and author of many articles in The Daily Worker and was the chairman of the editorial board of the London edition for several years. In 1937, Haldane had become a Marxist, and an open supporter of the Communist Party, but not yet a member of the Party. He would join the Party in 1942. Events in the Soviet Union, such as the rise of the anti-Mendelian agronomist Trofim Lysenko and the crimes of Stalin, may have caused him to break with the Communist Party later in life, although known records show his partial support of Lysenko and Stalin rather than criticism or condemnation. He left the Communist party in 1950, shortly after having toyed with standing for Parliament as a Communist Party candidate. However, his support for the Socialist ideal appears to be a pragmatic one. Writing in 1928, in On Being the Right Size, Haldane doubts whether the Socialist principle could be operated on the scale of the British Empire or the United States (or, implicitly, the Soviet Union): "while nationalization of certain industries is an obvious possibility in the largest of states, I find it no easier to picture a completely socialized British Empire or United States than an elephant turning somersaults or a hippopotamus jumping a hedge." As late as 1962, he would describe Joseph Stalin as "a very great man who did a very good job."

Haldane was a friend of the author Aldous Huxley, and was the basis for the biologist Shearwater in Huxley's novel Antic Hay. Ideas from Haldane's Daedalus, such as ectogenesis (the development of fetuses in artificial wombs), also influenced Huxley's Brave New World.

The most famous of Haldane's many students, John Maynard Smith, shared his mixture of political and scientific interests to some extent, but broke away from the Communist Party in 1956.

In 1952, he received the Darwin Medal from the Royal Society. In 1956, he was awarded the Huxley Memorial Medal of the Royal Anthropological Institute. Among other awards, he received the Feltrinelli Prize, an Honorary Doctorate of Science, an Honorary Fellowship at New College, and the Kimber Award of the U.S. National Academy of Sciences.

Haldane died on December 1, 1964. He willed that his body be used for study at the Rangaraya Medical College, Kakinada.

My body has been used for both purposes during my lifetime and after my death, whether I continue to exist or not, I shall have no further use for it, and desire that it shall be used by others. Its refrigeration, if this is possible, should be a first charge on my estate

* Wives: Charlotte Burghes (née Franken), Helen Spurway * He has an Erdős number of 5. * He is famous also for the (possibly apocryphal) response he gave when some theologians asked him what could be inferred about the mind of the Creator from the works of Creation: "An inordinate fondness for beetles". * Often quoted for saying, "My own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose." Haldane is sometimes misquoted as saying, "Not only is the universe stranger than we imagine, it is stranger than we can imagine" which should be attributed to Arthur Stanley Eddington. * "I had it [gastritis] for about fifteen years until I read Lenin and other writers, who showed me what was wrong with our society and how to cure it...Since then I have needed no magnesia." * C. S. Lewis wrote much of his three interplanetary space novels, The Space Trilogy, in response to Haldane, who Lewis found a very immoral man. The Space Trilogy comprises Out of the Silent Planet, Perelandra, and That Hideous Strength. Lewis modelled the character Weston, featured in Out of the Silent Planet and Perelandra, on Haldane. Haldane was one of those, along with Olaf Stapledon, Charles Kay Ogden, I. A. Richards, and H. G. Wells, whom Lewis accused of scientism, "the belief that the supreme moral end is the perpetuation of our own species, and that this is to be pursued even if, in the process of being fitted for survival, our species has to be stripped of all those things for which we value it—-of pity, of happiness, and of freedom." Shortly after the third book of the Ransom Trilogy appeared, J. B. S. Haldane criticized all three of them in an article entitled "Auld Hornie, F.R.S.". The title reflects the sarcastic tone of the article, Auld Hornie being the pet name given to the devil by the Scots and F.R.S. standing for "Fellow of the Royal Society". Lewis’s response, "A Reply to Professor Haldane", never published during his lifetime and apparently never seen by Haldane, demonstrated Haldane’s misunderstandings. By walking through each criticism, Lewis showed that he did not intend for all of his science to be totally accurate; after all, he was writing a romance. Then he indicated that he was attacking scientism, not scientists, by challenging the view of some that the supreme goal of our species is to perpetuate itself at any expense.

* Daedalus; or, Science and the Future (1924), E. P. Dutton and Company, Inc., a paper read to the Heretics, Cambridge, on February 4, 1923 ** second edition (1928), London: Kegan Paul, Trench & Co. * A Mathematical Theory of Natural and Artificial Selection, a series of papers beginning in 1924 * G.E. Briggs and J.B.S. Haldane (1925). A note on the kinetics of enzyme action, Biochem. J., 19: 338-339 *Callinicus: A Defence of Chemical Warfare (1925), E. P. Dutton *Possible Worlds and Other Essays (1927), Harper and Brothers, London: Chatto & Windus 1937 edition, Transaction Publishers 2001 edition: ISBN 0765807157 *Animal Biology (1929) Oxford: Clarendon *Enzymes (1930), MIT Press 1965 edition with new preface by the author written just prior to his death: ISBN 0262580039 *The Causes of Evolution (1932) *Science and Human Life (1933), Harper and Brothers, Ayer Co. reprint: ISBN 0836921615 *Science and the Supernatural: Correspondence with Arnold Lunn (1935), Sheed & Ward, Inc, *Fact and Faith (1934), Watts Thinker's Library *My Friend Mr Leakey (1937), Vigyan Prasar 2001 reprint: ISBN 8174800298 C. S. Lewis's "A Reply to Professor Haldane" is currently available in "On Stories and Other Essays on Literature," edited by Walter Hooper and published by Harcourt, Inc. (1982): ISBN 0-15-602768-2. *Air Raid Precautions (A.R.P.) {1938), Victor Gollancz *Marxist Philosophy and the Sciences (1939), Random House, Ayer Co. reprint: ISBN 0836911377 *Science and Everyday Life (1940), Macmillan, 1941 Penguin, Ayer Co. 1975 reprint: ISBN 0405065957 *Science in Peace and War (1941), Lawrence & Wishart, ltd *New Paths in Genetics (1941), George Allen & Unwin *Heredity & Politics (1943), George Allen & Unwin *Why Professional Workers should be Communists (1945), London: Communist Party (of Great Britain) In this four page pamphlet, Haldane contends that Communism should appeal to professionals because Marxism is based on the scientific method and Communists hold scientists as important; Haldane subsequently disavowed this position *Adventures of a Biologist (1947) *Science Advances (1947), Macmillan *What is Life? (1947), Boni and Gaer, 1949 edition: Lindsay Drummond *Everything Has a History (1951), Allen & Unwin *"Origin of Man", Nature, 176, 169 (1955) * "Cancer's a Funny Thing": New Statesman, 1964. This is a heartwarming poem (but unfortunately composed during what turned out to be his mortal illness) written to encourage others to consult a doctor when they experience the symptoms it describes. It begins: "I wish I had the voice of Homer/ To sing of rectal carcinoma,/ Which kills a lot more chaps, in fact,/ Than were bumped off when Troy was sacked." ....and ends "I know that cancer often kills,/ But so do cars and sleeping pills;/ And it can hurt one till one sweats,/ So can bad teeth and unpaid debts./ A spot of laughter, I am sure,/ Often accelerates one’s cure;/ So let us patients do our bit/ To help the surgeons make us fit"

* Bryson, Bill (2003) A Short History of Nearly Everything pp. 300-302; ISBN 0-552-99704-8 * Clark, Ronald (1968) JBS: The Life and Work of J.B.S. Haldane ISBN 0-340-04444-6 * Dronamraju, K. R. (editor) (1968) Haldane and Modern Biology Johns Hopkins University Press, Baltimore, Maryland. * Geoffrey Zubay et al, Biochemistry (2nd ed., 1988), enzyme kinetics, pp. 266-272; MacMillan, New York ISBN 0-02-432080-3

* An online copy of Daedalus or Science and the Future * A review (from a modern perspective) of The Causes of Evolution *Royal Society citation * Unofficial SJG Archive - People - JBS Haldane (1892-1964) Accessed 22 February 2006. Useful text but the likeness is not of JBS but of his father John Scott Haldane. * Haldane's contributions to science in India * Marxist Writers: J.B.S. Haldane * You can see and hear J.B.S. Haldane speak during the introduction of the rather disturbing Soviet film Experiments in the Revival of Organisms (1940) There are photographs of Haldane at *Photograph from 1946 Royal Society *JBS Haldane, on the Portraits of Statisticians page. The biography on the Marxist Writers page has a photograph of Haldane when younger. *My Friend Mr. Leakey - text - Haldane's most amusing imaginary acquaintance