The text discusses the genetic distance between populations and its relation to Wahlund's principle. It explains that when reproductively isolated subpopulations are combined, an excess of homozygous carriers of a gene arises due to differences in allele frequencies among subpopulations. This excess can be expressed as a function of genetic distances between subpopulations. The principle can be used to detect mixtures of seed lots, distinguishing bulking effects from inbreeding and assortative mating by analyzing genetic distances at multiple gene loci. Selection can complicate inference, so the method is best applied to dormant seed. Isozyme loci are recommended for this purpose due to their rarity of complete dominance. The text introduces a measure of genetic distance between two subpopulations, defined as half the sum of absolute differences in allele frequencies. This measure has properties such as symmetry, boundedness, and the triangular inequality. For two subpopulations, the variance in allele frequency is proportional to the square of the genetic distance. This allows the calculation of the excess of homozygotes after mixing subpopulations. The variance reaches its maximum when subpopulations are of equal size. Using observed homozygote frequencies, one can infer the proportion of each subpopulation in the mixture. For multiple subpopulations, the variance in allele frequency is derived from the squared expectation of the weighted mean allele frequency. This leads to a formula for the variance in terms of the genetic distances between subpopulations. The text provides a mathematical derivation of these relationships, showing how genetic distance can be used to understand and quantify the effects of subpopulation mixing on genetic structure.The text discusses the genetic distance between populations and its relation to Wahlund's principle. It explains that when reproductively isolated subpopulations are combined, an excess of homozygous carriers of a gene arises due to differences in allele frequencies among subpopulations. This excess can be expressed as a function of genetic distances between subpopulations. The principle can be used to detect mixtures of seed lots, distinguishing bulking effects from inbreeding and assortative mating by analyzing genetic distances at multiple gene loci. Selection can complicate inference, so the method is best applied to dormant seed. Isozyme loci are recommended for this purpose due to their rarity of complete dominance. The text introduces a measure of genetic distance between two subpopulations, defined as half the sum of absolute differences in allele frequencies. This measure has properties such as symmetry, boundedness, and the triangular inequality. For two subpopulations, the variance in allele frequency is proportional to the square of the genetic distance. This allows the calculation of the excess of homozygotes after mixing subpopulations. The variance reaches its maximum when subpopulations are of equal size. Using observed homozygote frequencies, one can infer the proportion of each subpopulation in the mixture. For multiple subpopulations, the variance in allele frequency is derived from the squared expectation of the weighted mean allele frequency. This leads to a formula for the variance in terms of the genetic distances between subpopulations. The text provides a mathematical derivation of these relationships, showing how genetic distance can be used to understand and quantify the effects of subpopulation mixing on genetic structure.