NOTE 14B: This standard calculation gives the broad-sense heritability. Note that it applies only to this backcross population: The heritability in the F₂, for example, would be higher and would include dominance components (because three genotypes would be present at each gene, not two as in a backcross). The assumption that the environmental variance in the F₁ is the same as that in the backcross is dubious because the genotypes are different and, in particular, because the trait mean in the F₁ is lower than in the backcross (2.25 g vs. 5.30 g). We would expect the variance to be higher if the mean is higher.