F-statistics

F-statistics

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http://en.wikipedia.org/wiki/F-statistics

In population genetics, F-statistics (also known as fixation indices) describe the statistically expected level of heterozygosity in a population; 

개체군 유전학 용어인 F-statistics(fixation indices)는 어느 한 개체군내에서의 heterozygosity에 대한 확률기대치를 의미한다.

more specifically the expected degree of (usually) a reduction in heterozygosity when compared to Hardy–Weinberg expectation.

더 상세히는 개체군내의 Hardy-Weinberg expectation 과 비교한 실제 heterozygosity의 감소치를 의미한다.

F-statistics can also be thought of as a measure of the correlation between genes drawn at different levels of a (hierarchically) subdivided population. 

F-statistics는 계층적으로 나뉘어진 개체군들의 (유전자들간의) 상관관계를 나타내는 측정치로도 생각할수도 있다. 

This correlation is influenced by several evolutionary processes, such as mutation, migration, inbreeding, natural selection, or the Wahlund effect, 

but it was originally designed to measure the amount of allelic fixation owing to genetic drift.

이 상관관계는 mutation, migration, inbreeding, natural selection, Wahlund effect에 의해 영향을 받을 수 있으며,

원래는 genetic drift에 의한 allelic fixation을 측정하기 위해 고안되었다.

The concept of F-statistics was developed during the 1920s by the American geneticist Sewall Wright, who was interested in inbreeding in cattle. 

However, becausecomplete dominance causes the phenotypes of homozygote dominants and heterozygotes to be the same, 

it was not until the advent of molecular genetics from the 1960s onwards that heterozygosity in populations could be measured.

http://academic.reed.edu/biology/professors/srenn/pages/research/2011_students/sean/SM_thesis.html

Fig. B – Schematic of F-statistics for a subdivided population. 

F-statistics reflect the probability that two paired alleles are identical by descent, 

as indicated across the three distances IS (for an individual in a subdivided population), 

ST (averaged for individuals in subpopulations, across the entire grouping of subpopulations), 

and IT (for an individual in the entire grouping of all subpopulations). 

For any of these parameters, a calculation of "0" indicates the population is entirely outbred,

 while a population with parameter "1" is entirely inbred.

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