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Family losses following truncation selection in populations of half-sib families

Informally Refereed

Abstract

Family losses during truncation selection may be sizable in populations of half-sib families. Substantial losses may occur even in populations containing little or no variation among families. Heavier losses will occur, however, under conditions of high heritability where there is considerable family variation. Standard deviations and therefore variances of family loss, however, change little over the range of heritability. Increasing the intensity of selection causes the mean loss to increase but has little effect on the standard deviation of loss. As the number of families in the base population rises, both the mean loss and variance of loss increase, but the proportion of families lost remains almost constant. Some families will be lost in almost all selection operations, even those undertaken under conditions of low expected family losses, since variance of family loss is at moderate levels over a wide range of conditions.

Citation

Roberds, J. H.; Namkoong, G.; Kang, H. 1980. Family losses following truncation selection in populations of half-sib families. Silvae Genetica ISSN, Vol. 29, 4 p.
https://www.fs.usda.gov/research/treesearch/9200