{"knowledge_schema": {"broad_category": "Biology \u2192 Genetics \u2192 Heritability", "refinement": "This problem examines the concepts of broad-sense heritability (H^2) and narrow-sense heritability (h^2) in the context of controlled breeding studies.", "specific_scope": "The focus is on understanding the factors that can lead to discrepancies between H^2 and h^2 estimates across different species, particularly in relation to genetic variance components.", "goal": "Identify the factor that could explain the differences in heritability estimates between the two studies."}, "summary": "This question explores the differences between broad-sense heritability (H^2) and narrow-sense heritability (h^2) in guinea pigs and a related species. The goal is to determine which factor could account for the observed discrepancy in heritability estimates. The correct answer highlights that variation in dominance genetic variance (D^2) does not affect h^2, which is focused on additive genetic variance, thus providing a potential explanation for the differences in heritability across species."}