To determine ONLY the genetic value, what must we do?

To determine ONLY the genetic value, what must we do?

• A. Remove environmental noise by expressing genetic values as deviations from the group mean
• B. Increase sample size
• C. Average phenotypic values
• D. Ignore non-additive effects

Answer: (A)

To determine the genetic value, you need to separate genotype from environment by removing environmental noise. Expressing genetic values as deviations from the group mean does just that: it centers phenotypic data so the shared environmental influence is subtracted out, leaving the differences that arise from genotype itself. In practice, phenotype equals genetic value plus environmental effect, and subtracting the group mean effectively removes the environmental offset, highlighting the additive genetic differences among individuals. Increasing sample size helps precision but doesn’t isolate the genetic component by itself. Averaging phenotypic values blends genetic and environmental effects rather than separating them. Ignoring non-additive effects overlooks parts of the genetic contribution (like dominance and epistasis) and doesn’t address environmental noise, so it doesn’t yield the true genetic value.

To determine the genetic value, you need to separate genotype from environment by removing environmental noise. Expressing genetic values as deviations from the group mean does just that: it centers phenotypic data so the shared environmental influence is subtracted out, leaving the differences that arise from genotype itself. In practice, phenotype equals genetic value plus environmental effect, and subtracting the group mean effectively removes the environmental offset, highlighting the additive genetic differences among individuals.

Increasing sample size helps precision but doesn’t isolate the genetic component by itself. Averaging phenotypic values blends genetic and environmental effects rather than separating them. Ignoring non-additive effects overlooks parts of the genetic contribution (like dominance and epistasis) and doesn’t address environmental noise, so it doesn’t yield the true genetic value.