Utilisateur:Tooony/fisher

Biographie

Jeunesse

Fisher naît dans le quartier de East Finchley à Londres, de George et Katie Fisher. Son père était un marchand d'art. Il eut une enfance heureuse, avec trois sœurs et un frère aînées. Sa mère meurt quand il a 14 ans. Son père perd son affaire, 18 mois plus tard.

Bien que Fisher ait une très mauvaise vue, il fut un étudiant précoce. Il remporte la médaille Neeld (une compétition de mathématiques) à l'âge de 16 ans. En raison de sa mauvaise vue, il étudia les mathématiques sans papier ni crayons, ce qui développa chez lui une capacité à visualiser les problèmes en termes géométriques, sans utiliser de manipulations algébriques. Il avait une réputation légendaire à produire des résultats sans passer par les étapes intermédiaires. Il s'intéressa fortement à la biologie et spécialement à l'évolution.

En 1909 il fut accepté au Gonville and Caius College de l'Université de Cambridge. Il y apprend les principes nouvellement re-décourverts de la théorie de Mendel ; il voyait dans la biométrie et la statistique un moyen de réconcilier la nature discontinue de l'hérédité mendélienne et les variations continues et l'évoltion graduelle. Il s'intéressa beaucoup à l'eugénisme, qu'il voyait comme un problème social et scientifique, qui étaient en relation avec la génétique et les mathématiques en même temps.

En 1911 il s'engagea dans le développment de la société eugénique de l'Université de Cambridge hcomme John Maynard Keynes, R.C. Punnett et Horace Darwin (fils de Charles Darwin). The group was active, and held monthly meetings, often featuring addresses by leaders of mainstream eugenics organizations, such as the Eugenics Education Society of London, founded by Charles Darwin's half-cousin, Francis Galton in 1909.

After graduating in 1912, Fisher was eager to join the army in anticipation of Great Britain's entry into World War I; however, he failed the medical examinations (repeatedly) because of his eyesight. Over the next six years, he worked as a statistician for the City of London. For his war work, he took up teaching physics and mathematics at a series of public schools, including Bradfield College in Berkshire, as well as aboard H.M. Training Ship Worcester. Major Leonard Darwin (another of Charles Darwin's sons) and an unconventional and vivacious friend he called Gudruna were almost his only contacts with his Cambridge circle. They sustained him through this difficult period. A bright spot in his life was that Gudruna matched him to her sister Eileen Guinness; they married in 1917 when she was only 17. With the sisters' help, he set up a subsistence farming operation on the Bradfield estate, where they had a large garden and raised animals, learning to make do on very little. They lived through the war without ever using their food coupons.

During this period, Fisher started writing book reviews for the Eugenic Review and gradually increased his interest in genetic and statistical work. He volunteered to undertake all such reviews for the journal, and was hired to a part-time position by Major Darwin. He published several articles on biometry during this period, including the ground-breaking "The Correlation Between Relatives on the Supposition of Mendelian Inheritance" , written in 1916 and published in 1918. This paper laid the foundation for what came to be known as biometrical genetics, and introduced the very important methodology of the analysis of variance, which was a considerable advance over the correlation methods used previously. The paper showed very convincingly that the inheritance of traits measurable by real values, the values of continuous variables, is consistent with Mendelian principles.

With the end of the war he went looking for a new job, and was offered one at the famed Galton Laboratory by Karl Pearson. Because he saw the developing rivalry with Pearson as a professional obstacle, however, he accepted instead a temporary job as a statistician with a small agricultural station in the country in 1919.

Stained glass window in the dining hall of Caius College, in Cambridge, commemorating Ronald Fisher and representing a Latin square.