ecology 1. the influence of a dominant species 2. the extent to which a given species or life form predominates in a community because of its size, abundance, or cover, and effects on the fitness of associated species —note dominance is interpreted in two ways for vegetation classification purposes: (a) where one or more vegetation strata or life-forms covers greater than 25 percent, the life form greater than 25 percent constituting the uppermost canopy is referred to as the dominant life form (b) where no vegetation life form covers greater than 25 percent, the life form with the highest percent canopy cover is referred to as the dominant life form; in the case of a tie, the upper canopy is referred to as the dominant life form —see life form 3. genetics the masking of the action of one allele by its alternate allele —note if a completely dominant allele for red color appears with a recessive one for white, the phenotype will be red; if this dominance is partial, the color may tend toward deep pink; if there is no dominance, the color will be intermediate —see dominance, epistasis, genetic variation, heterozygous, lethal gene, phenotype, simple Mendelian inheritance, xeniaThis definition last updated 10/25/2008