Ronald Fisher

Sir Ronald Aylmer Fisher (1890 to 1962) was a British statistician and geneticist who helped found modern statistics and the mathematical theory of population genetics. He reconciled Mendelian inheritance with Darwin's theory of natural selection and is a central figure in the modern synthesis.

At the Rothamsted agricultural station, Fisher developed the analysis of variance (ANOVA), the principles of experimental design such as randomization, the method of maximum likelihood and the use of significance tests, which gave the field of statistics much of its modern shape. His book Statistical Methods for Research Workers (1925) became a standard guide for biologists.

In a 1918 paper Fisher showed that continuous traits such as height can be explained by many genes following Mendel's laws, ending an argument between Mendelians and biometricians. His 1930 book The Genetical Theory of Natural Selection set out the fundamental theorem of natural selection and ideas such as the sex ratio principle and sexual selection by runaway.

With Sewall Wright and J. B. S. Haldane, Fisher is counted among the founders of population genetics, which later included genetic drift as a force alongside selection. He supported eugenics and doubted early evidence that smoking caused lung cancer, positions that are criticized today. His methods remain basic tools in biostatistics.

• Modern Synthesis — the unification he helped build
• Population Genetics — the field he helped found
• Biostatistics — the applied statistics of biology