Pub. date: 2008 | Online Pub. Date: November 27, 2007 | DOI: 10.4135/9781412953948 | Print ISBN: 9781412928168 | Online ISBN: 9781412953948| Publisher:SAGE Publications, Inc.About this encyclopedia
F. John Meaney & Cynthia Taylor
In genetics, heritability is the amount of phenotypic variation in a population that is attributable to individual genetic differences. Heritability, in a broad, general sense, is the ratio of variation due to differences among genotypes to the total phenotypic variation for a character or trait in a population. It is expressed as The range of values for heritability estimates is 0 to 1. If H = 1, then we are able to say that all variation in a population is due to differences or variation among genotypes (i.e., there is no environmentally caused variation). On the other hand, if H = 0, there is no genetic variation. In this case, all variation in the population is from differences in environments during the life experience of individuals. In other words, we can say that all individuals are the same with regard to the effect of their genes on phenotypic variance. The ...