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A E Stark

Publications and source records attributed to A E Stark.

7 recordsLinked to original sources
PubMed1977

A model of assortative mating with partial dominance.

A model of assortative mating incorporating partial dominance is proposed for a single locus with two alleles. It is derived by starting from an arbitrary genotypic distribution and finding symmetric and non-selective mating frequencies which duplicate this distribution. Numerical values are imputed to genotypes, the homozygotes having numerically equal values, opposite in sign, and the heterozygote having a value determined by the gene and heterozygote frequencies. The model is specified in a canonical form which reveals the correlation between mates based on genotypic values, and relates the correlation to the fixation index. It permits negative as well as positive values of the fixation index. It is shown that this general model includes several particular cases, in equilibrium phase, occurring in the literature.

Alleles↗
PubMed1977

Comments on the Penrose-Stanton model of assortative mating.

A single-locus model of assortative mating proposed by Penrose and extended by Stanton is analysed. It is shown that the formulae giving values of correlations between males and relatives derived by Stanton apply to a general class of symmetric, non-selective mating schemes in equilibrium when genotypes have additive values. The canonical form of Stanton's system is derived, revealing that the assignment of additive values of genotypes does not apply also to the canonical vectors.

Crosses, Genetic↗
PubMed1976

Hardy-Weinberg law: asymptotic approach to a generalized form.

The equilibrium frequencies of a generalized Hardy-Weinberg law are approached at a geometric rate under assortative mating, irrespective of the initial genotypic frequencies. The asymptotic form is similar to that of Wright, and the pattern of assortative mating is based on deviations from the mean genotypic value.

Gene Frequency↗
PubMed1976

A model for assortative mating.

It is shown that a generalization of the Hardy-Weinberg law of the proportions of genotypes of the kind given by Wright (1922) is maintained in equilibrium by a pattern of assortative mating suggested by Fisher (1918) and elaborated by Malécot (1939, 1948).

Genetics, Population↗
PubMed1976

On the method of Penrose of estimating the number of effective factors contributing to a character.

Penrose (1969) presented a method of estimating the number of effective factors contributing to a quantitative character. The method uses samples of parent-child and sib-sib phenotypic values. More detailed mathematical analysis shows that his assertions regarding the method are correct under the assumptions which he made, provided that his phrase 'the same quantitative effect' is interpreted to mean 'makes an equal contribution to the variance'.

Alleles↗
PubMedDate not supplied

Marital correlation for anthropometric characteristics in Brazilian Indians.

A total of 336 couples from 10 villages of three Brazilian Indian tribes was studied in relation to 15 anthropometric characteristics. Correlation coefficients between husband and wife were generally positive, none of the negative ones reaching a probability level of 1% or less. Thirteen correlations attained this level, but none of the traits behaved similarly in the three tribes. Height adjustment taking into consideration the correlation between mates for age did not much alter the correlation coefficients, but a larger influence was observed after allowance for temporal effects. A significant pair of canonical variables was obtained considering sitting height and leg length, but factors related to facial and bone form, extracted through principal-components analysis, yielded correlations insignificantly different from zero.

Anthropometry↗