Dominance variance: associations with selection and fitness

• Published in: Heredity Vol. 75; no. 5; pp. 530 - 540
• Main Authors: Crnokrak, P, Roff, D.A
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.11.1995; Nature Publishing
• Subjects: anatomy and morphology; animals; artificial selection; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Classical genetics, quantitative genetics, hybrids; crops; Cytogenetics; domestic animals; dominance; Ecology; Evolutionary Biology; frequency distribution; Fundamental and applied biological sciences. Psychology; genetic variance; Genetics of eukaryotes. Biological and molecular evolution; Human Genetics; insects; life cycle (organisms); Methods, theories and miscellaneous; morphological traits; natural selection; original-article; outcrossing; phenotypic variance; Plant Genetics and Genomics; plant morphology; quantitative traits; selection pressure; variance; wild plants; wild relatives; dominance variance; genetic variation; selection; fitness; Statistical analysis; Quantitative character; Artificial selection; Genetic parameter; Heritability; Variance; Fitness; Natural selection
• ISSN: 0018-067X; 1365-2540
• DOI: 10.1038/hdy.1995.169

Strong directional and to some degree stabilizing, selection usually erodes only additive genetic variance while not affecting dominance variance. Consequently, traits closely associated with fitness should exhibit high levels of dominance variance. In this study we compile a large number of estimates of dominance variance to determine if traits that are subject to strong selection and/or are closely associated with fitness have higher levels of dominance variance than traits less subject to selection pressure. Estimates were taken from the literature for both wild and domestic species and each group was treated separately. Traits closely associated with fitness (life history) had significantly higher dominance components than did traits more distantly related to fitness (morphology) for wild species. No significant differences were found between life history and morphological traits for domestic species. Traits that were known to have been subject to intense directional selection (morphological traits for domestic species) had significantly higher dominance estimates than did traits that were assumed not to have been subject to strong selection (morphological traits for wild outbred species). The results are discussed with respect to the maintenance of heritable variation and the bias introduced in the calculation of the full-sib heritability estimate by high levels of dominance variance.