selection coefficient

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se·lec·tion co·ef·fi·cient (s),

the proportion of progeny or potential progeny not surviving to sexual maturity; usually defined artificially by expressing the fitness of a phenotype as a fraction of the mean or optimal fitness to give the relative fitness, and subtracting this fraction from unity. If the mean size of family in the population is 3.2 and that for a particular genotype is 2.4 then the fitness of the phenotype is 2.4/3.2 = 0.75 and the selection coefficient = 1 - 0.75 = .25.

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se·lec·tion co·ef·fi·cient

(s) (sĕ-lek'shŭn kō'ĕ-fish'ĕnt)

The proportion of progeny or potential progeny not surviving to sexual maturity; usually defined artificially by expressing the fitness of a phenotype as a fraction of the mean or optimal fitness to give the relative fitness, and subtracting this fraction from unity.If the mean size of family in the population is3.2 and that for a particular genotype is 2.4,then the fitness of the phenotype is 2.4/3.2 =0.75, and the selection coefficient =1- 0.75 =.25 = 5.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

selection coefficient

see SELECTION PRESSURE.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

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Models of quantitative genetic variation that depend on overdominance in fitness of the loci involved thus predict that this variation will be greatly reduced in populations with very high rates of selfing, although there may be little effect below some selfing rate that depends on the selection coefficients at the loci involved.

Quantitative genetics in plants: the effect of the breeding system on genetic variability

The effective selection coefficient [s.sub.m] acting on m at the quasi-equilibrium is

Deleterious mutation and the evolution of genetic life cycles

In the linear additive model, therefore, we can easily calculate the additive genetic variance and selection coefficient based on this theorem (Price, 1972; Hartl, 1988; Ewens, 1989).

The prediction of the expected current selection coefficient of single nucleotide polymorphism associated with Holstein milk yield, fat and protein contents

The change of recessive allele frequency as the function of this frequency in the previous generation q and the selection coefficient s is calculated as (Crow & Kimura, 1970: eq.

When a fly has to fly to reproduce: selection against conditional recessive lethals in Drosophila

This position is supported by the fact that estimates of the degree of inbreeding depression for fitness in Drosophila are in very good agreement with expectations based on the estimates of mutation rates, selection coefficients, and coefficients of dominance obtained from mutation-accumulation experiments (Simmons and Crow 1977; D.

Mutation, selection, and the maintenance of life-history variation in a natural population

Selection coefficients and differentials were considered to be significantly different from zero only if the 95% confidence interval did not include zero.

Natural selection and ecotypic differentiation in Impatiens pallida

The resulting selection coefficients (s = 1 - [omega]) indicate that immigrants invading mature demes face much stronger selection gradients than invaders of young deme s (Table 4).

SPATIOTEMPORAL VARIATION IN LEAFMINER POPULATION STRUCTURE AND ADAPTATION TO INDIVIDUAL OAK TREES

The [[Tau].sub.j] are a common type of kin selection coefficient, the slope of recipient genotype on actor genotype.

The price equation, fisher's fundamental theorem, kin selection, and causal analysis

With synergistic epistasis, the selection coefficients of individual mutations are effectively magnified as deleterious mutations accumulate in a genome, and for mutations with equivalent effects, this has the effect of progressively reducing the probability of fixation, eventually to zero.

Mutation and extinction: the role of variable mutational effects synergistic epistasis, beneficial mutations, and degree of outcrossing

The selection coefficient of the advantageous allele was generally small, ranging from 0.002 to 0.02.

Evolution of a beneficial allele under partial selfing and inbreeding depression

The selection coefficient estimates do not rely upon distributional assumptions (Lande and Arnold 1983), but the standard parametric significance tests assume normality of residuals (Neter et al.

Intrasexual competition alone favors a sexually dimorphic ornament in the rubyspot damselfly Hetaerina americana

The magnitude of the selection coefficient, S, for selection exerted on corolla flare by bumblebees at seed set was calculated from the slope of the regression line (Lande and Arnold 1983).

Rates of floral evolution: adaptation to bumblebee pollination in an alpine wildflower, Polemonium viscosum