A hypothetical study investigated the vitamin A content and the cholesterol content of eggs from a large population of chickens. The following variances (V) were calculated.

Calculate the narrow-sense heritability (h²) for both traits. <>

Key Concepts

Narrow-Sense Heritability (h²)

Narrow-sense heritability (h²) quantifies the proportion of phenotypic variance in a trait that can be attributed to additive genetic variance. It is crucial for predicting the response to selection in breeding programs. The formula for h² is h² = Va / Vp, where Va is the additive genetic variance and Vp is the total phenotypic variance.

Phenotypic Variance (Vp)

Phenotypic variance (Vp) is the total variance observed in a trait within a population, resulting from both genetic and environmental factors. It can be partitioned into genetic variance (which includes additive, dominance, and interaction effects) and environmental variance. Understanding Vp is essential for calculating heritability and assessing the influence of genetics versus environment.

Additive Genetic Variance (Va)

Additive genetic variance (Va) refers to the portion of genetic variance that contributes to the average effects of alleles on a trait. It is the sum of the effects of individual alleles and is important for predicting how traits will respond to selection. High Va indicates that selection can effectively change the trait in future generations, making it a key component in heritability calculations.