A mathematical theory that aims to predict the responses to natural selection, given data on phenotypes and relationships among individuals. In recent times, the theory has been extended to include the analysis of quantitative trait loci. Quantitative traits are those that are under the influence of a number of genes, and their mapping onto a location on a chromosome requires the accurate identification of phenotypical pedigree and marker data from a large number of related individuals. In general, quantitative genetics builds on some of the mathematical formulations in population genetics. The theory developed from the honours thesis of Ronald A. Fisher (1890-1962) when he was an undergraduate at Cambridge University.
See Behavior genetics, Modern synthesis, Polygenic mode of inheritance, Polygenes, Population genetics, Theory of natural selection, Trait