Question

Family selection is better than individual selection when phenotypic correlation is

• A. medium
• B. high
• C. low
• D. very high

Hint:

Family selection is particularly valuable for traits that are difficult or impossible to measure on the candidate itself, such as carcass quality or sex-limited traits.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Breeding programs can use different selection methods, such as individual selection (mass selection) or family selection, to identify superior animals.
The relative efficiency of family selection compared to individual selection depends on the heritability of the trait and the phenotypic correlation among family members.

Step 2: Detailed Explanation:
Let us compare individual and family selection:
Individual Selection: Best suited for traits with high heritability, where an animal's own phenotype is a reliable indicator of its breeding value.
Family Selection: Best suited for traits with low heritability and low phenotypic correlation among family members.
When heritability is low, an individual's phenotype is heavily influenced by environmental noise, making individual selection inefficient.
However, averaging the phenotypes of family members helps cancel out individual environmental variations.
This makes the family average a more reliable indicator of breeding value than an individual's own performance.
Therefore, family selection is more efficient than individual selection when the phenotypic correlation among family members is low.

Step 3: Final Answer:
Family selection is better than individual selection when the phenotypic correlation is low.