Compare and contrast broad sense heritability and narrow sense heritability, giving an example of each measurement and identifying how the measurement is used.

Key Concepts

Broad Sense Heritability

Broad sense heritability (H²) measures the proportion of phenotypic variance in a trait that can be attributed to genetic variance, including additive, dominance, and interaction effects among alleles. It provides a comprehensive view of genetic influence on traits, but does not distinguish between different types of genetic contributions. For example, in a study of plant height, broad sense heritability would consider all genetic factors affecting height, making it useful for understanding overall genetic potential.

Narrow Sense Heritability

Narrow sense heritability (h²) specifically quantifies the proportion of phenotypic variance that is due to additive genetic variance alone. This measure is crucial for predicting the response to selection in breeding programs, as it reflects the heritable traits that can be passed on to the next generation. For instance, in livestock breeding, narrow sense heritability would focus on traits like milk production, helping breeders select for animals that will pass on desirable traits.

Applications of Heritability Measurements

Heritability measurements are essential in genetics for understanding the genetic basis of traits and guiding breeding strategies. Broad sense heritability is often used in ecological and evolutionary studies to assess the potential for evolution in populations, while narrow sense heritability is critical in agricultural and animal breeding contexts, where it helps predict the effectiveness of selection. Both measurements inform researchers and breeders about the genetic architecture of traits and their potential for improvement.