De Finetti diagram

A de Finetti diagram. The curved line is the expected Hardy-Weinberg frequency as a function of p.

A de Finetti diagram is a ternary plot used in population genetics. It is named after the Italian statistician Bruno de Finetti (1906–1985) and is used to graph the genotype frequencies of populations, where there are two alleles and the population is diploid. It is based on an equilateral triangle, and Viviani's theorem concerning any point within the triangle, and the three lines from that point that are perpendicular to the sides of the triangle. The sum of the lengths of the lines is a fixed value, regardless of the position of the point. This value (the sum of the lengths) is set to be 1.

Applications in genetics

The de Finetti diagram has been put to extensive use in population genetics by A.W.F. Edwards in his book Foundations of Mathematical Genetics. In its simplest form the diagram can be used to show the range of genotype frequencies for which Hardy-Weinberg equilibrium is satisfied. A.W.F. Edwards and Chris Cannings extended its use to demonstrate the changes that occur in allele frequencies under natural selection.

See also

Wahlund effect

References

• Cannings C., Edwards A.W.F. (1968) "Natural selection and the de Finetti diagram" Ann Hum Gen 31:421-428
• Edwards, A.W.F. (2000) Foundations of Mathematical Genetics 2nd Edition, Cambridge University Press. ISBN 9780521775441

External links

• Online plotting of de Finetti diagrams for population genetics (also calculates Hardy Weinberg equilibrium statistics)

This applied mathematics-related article is a stub. You can help Wikipedia by expanding it.v · Categories: Population genetics Diagrams Genetics stubs Applied mathematics stubs Wikimedia Foundation. 2010. Игры ⚽ Нужно решить контрольную? Jacques d'Adelswärd-Fersen Dysphania ambrosioides Look at other dictionaries: Bruno de Finetti — Born 13 June 1906(1906 06 13) Innsbruck, Austria …   Wikipedia De Finetti — usually refers to the Italian probabilist and statistician Bruno de Finetti, noted for the operational subjective conception of probability. His works include: de Finetti s theorem, which explains why exchangeable observations are conditionally… …   Wikipedia Mathematical diagram — This article is about general diagrams in mathematics. For diagrams in the category theoretical sense, see Diagram (category theory). Euclid s Elements, ms. from Lüneburg, A.D. 1200 Mathematical diagrams are diagrams in the field of mathematics,… …   Wikipedia Hardy–Weinberg principle — for two alleles: the horizontal axis shows the two allele frequencies p and q and the vertical axis shows the genotype frequencies. Each graph shows one of the three possible genotypes. The Hardy–Weinberg principle (also known by a variety of… …   Wikipedia Plot (graphics) — Scatterplot of the eruption interval for Old Faithful (a geyser). A plot is a graphical technique for representing a data set, usually as a graph showing the relationship between two or more variables. The plot can be drawn by hand or by a… …   Wikipedia List of mathematics articles (D) — NOTOC D D distribution D module D D Agostino s K squared test D Alembert Euler condition D Alembert operator D Alembert s formula D Alembert s paradox D Alembert s principle Dagger category Dagger compact category Dagger symmetric monoidal… …   Wikipedia Ternary plot — A ternary plot, ternary graph, triangle plot, simplex plot, or de Finetti diagram is a barycentric plot on three variables which sum to a constant. It graphically depicts the ratios of the three variables as positions in an equilateral triangle.… …   Wikipedia Wahlund effect — In population genetics, the Wahlund effect refers to reduction of heterozygosity in a population caused by subpopulation structure. Namely, if two or more subpopulations have different allele frequencies then the overall heterozygosity is reduced …   Wikipedia Genotype frequency — In population genetics, the genotype frequency is the frequency or proportion (i.e. 0 < f < 1) of genotypes in a population.It may be denoted thus:f(mathbf{AA}) Compare allele frequency.The Hardy Weinberg law predicts genotype frequencies from… …   Wikipedia List of triangle topics — This list of triangle topics includes things related to the geometric shape, either abstractly, as in idealizations studied by geometers, or in triangular arrays such as Pascal s triangle or triangular matrices, or concretely in physical space.… …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”