Effect of Inbreeding on Heritability
In case of inbreeding, heritability tends to-
- Decline — Correct Answer
- Increase
- Both
- None
Explanation:
Correct Answer: Decline
Inbreeding increases homozygosity, which reduces the additive genetic variance (VA) and total genotypic variance (VG) within a population. Since h² = VG / VP and VG decreases while VE remains relatively constant, heritability declines with inbreeding.
Inbreeding → Heritability Relationship
- Inbreeding increases homozygosity → all individuals become genetically similar → VG decreases
- h² = VG / (VG + VE); as VG → 0 (full inbreeding), h² → 0
- Paradox: Inbreeding does NOT help improve h² — it actually reduces it
Best Way to Increase h²
- Correct method: Reduce VE by providing a uniform environment
- Incorrect method: Inbreeding (it reduces VG and therefore reduces h²)
Other Effects of Inbreeding
| Parameter | Effect of Inbreeding |
|---|---|
| Homozygosity | Increases |
| Heterozygosity | Decreases |
| Genetic variance (VG) | Decreases |
| Heritability (h²) | Decreases |
| Prepotency | Increases |
| Inbreeding depression | Increases |
📚 About this Topic — Animal Genetics & Breeding
This multiple choice question is from Animal Genetics & Breeding, Animal Refresher. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Genetics & Breeding to strengthen your preparation.
