The Demopædia Encyclopedia on Population is under heavy modernization and maintenance. Outputs could look bizarre, sorry for the temporary inconvenience

Multilingual Demographic Dictionary, second unified edition, English volume

Selective value

Multilingual Demographic Dictionary, second unified edition, English vol.
(Redirected from Value, fitness)
Jump to: navigation, search
Selective value  (SELECTIVE value)


The probability that an individual of reproductive age will have a given number of offspring who also attain reproductive age may depend on his genotype (912-1). This differential reproduction is called selection 1. The selective value 2 or fitness value 2 of a genotype is the relative number of children of individuals with the genotype who survive to reproductive age. The mean selective value 3 or fitness 3 of a population is equal to the average of the selective values for the genotypes of its members. The genetic load 4 of the population is the relative decline in the mean value of fitness resulting from the presence of different genotypes with varying fitness values. Random fluctuation of the frequency with which a specific gene is found in different generations of a population is called the genetic drift 5. The gene structure 6 of a population refers to the distribution of the frequencies of different alleles (911-5) on a given locus (911-4) within the members of the population. The genotypic structure 7 of a population refers to the distribution of different genotypes on the same locus. More...