If after several rounds of artificial selection all alleles affecting the trait are fixed or lost, the narrow-sense heritability (h^{2}) of a trait is

h^2 = 0

Explanation:

When trait variance is a result of additive genetic factors, it is referred to as 'narrow sense heritability' or h^2. This estimate falls within a range of 0 to 1. h^2 is significant in indicating the evolutionary potential of a certain trait under study. Heritability value close to zero means that the variation in that trait is predominantly a result of environmental factors.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides