Hybrid vigor is best described as

• A. Genetic drift
• B. Mutation
• C. Hybrid vigor
• D. Inbreeding depression

Answer: (C)

Hybrid vigor, or heterosis, refers to the improved or increased performance of crossbred offspring compared with the average of their purebred parents. This happens because crossing genetically different parents boosts heterozygosity, which helps mask deleterious recessive alleles and combines favorable alleles from each line. In practical livestock terms, crossbred animals often show better growth, fertility, survivability, and overall robustness.

This isn’t about random changes in allele frequencies (genetic drift), the introduction of new traits from new mutations (mutation), or a decline in fitness from inbreeding (inbreeding depression). It’s the enhanced performance seen when diverse genetics are combined in the offspring.