What important factor does broad-sense heritability attribute phenotypic variation to?

Broad-sense heritability is defined as the proportion of phenotypic variance in a population that can be attributed to genetic variance. This includes not just additive genetic variance, which refers to the combined effects of individual alleles, but also dominance variance and gene-by-environment interactions. Thus, it encompasses all genetic influences that contribute to an individual's phenotype, making it a comprehensive measure of the genetic basis of phenotypic variation within a population.

While environmental factors, learning opportunities, and social interactions can significantly affect phenotypic traits, broad-sense heritability specifically focuses on the genetic component. Understanding this concept is fundamental in fields like quantitative genetics, as it helps researchers and geneticists determine how traits may respond to selection and how much of a trait's variability can be passed on to future generations.