In animal and plant breeding, truncation selection is a standard method in
selective breeding
Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant mal ...
in selecting animals to be bred for the next generation. Animals are ranked by their phenotypic value on some trait such as milk production, and the top percentage is reproduced. The effects of truncation selection for a continuous trait can be modeled by the standard
breeder's equation
Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of ''variation'' in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of heri ...
by using
heritability
Heritability is a statistic used in the fields of breeding and genetics that estimates the degree of ''variation'' in a phenotypic trait in a population that is due to genetic variation between individuals in that population. The concept of h ...
and
truncated normal distribution
In probability and statistics, the truncated normal distribution is the probability distribution derived from that of a normally distributed random variable by bounding the random variable from either below or above (or both). The truncated no ...
s. On a binary trait, it can be modeled easily using the
liability threshold model In mathematical or statistical modeling a threshold model is any model where a threshold value, or set of threshold values, is used to distinguish ranges of values where the behaviour predicted by the model varies in some important way. A particula ...
. It is considered an easy and efficient method of breeding.
Computer science
In computer science, truncation selection is a
selection method used in
genetic algorithm
In computer science and operations research, a genetic algorithm (GA) is a metaheuristic inspired by the process of natural selection that belongs to the larger class of evolutionary algorithms (EA). Genetic algorithms are commonly used to gene ...
s to select potential candidate solutions for recombination modeled after the breeding method.
In truncation selection the candidate solutions are ordered by fitness, and some proportion, ''p'', (e.g. ''p'' = 1/2, 1/3, etc.) of the fittest individuals are selected and reproduced 1/p times. Truncation selection is less sophisticated than many other selection methods, and is not often used in practice. It is used in Muhlenbein's
Breeder Genetic Algorithm.
References
"Chapter 14: Short-term Changes in the Mean: 2. Truncation and Threshold Selection"* Crow 2010
"On epistasis: why it is unimportant in polygenic directional selection"* Visscher et al. 2008
"Heritability in the genomics era - concepts and misconceptions"* Visscher 2016
"Human Complex Trait Genetics in the 21st Century"* Weight & Harpending 2016
"Some Uses of Models of Quantitative Genetic Selection in Social Science"* Frost & Harpending 2015
"Western Europe, state formation, and genetic pacification"
Genetic algorithms
Animal breeding
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