Introduction to Quantitative Genetics

Heritability

The general term that describes the proportion of the genetic variance to the total variance is heritability.

Boad-sense heritability is the ratio of total genetic variance to total phenotypic variance.

H² = V_G/V_P

Narow-sense heritability is the ratio of additive genetic variance to the total phenotypic variance.

h² = V_A/V_P

Important points about heritability

1. The heritability estimate is specific to the population and environment you are analyzing.
2. The estimate is a population, not an individual parameter.
3. Heritability does not indicate the degree to which a trait is genetic, it measures the proportion of the phenotypic variance that is the result of genetic factors.