Table 1 Symbols and their meaning
SymbolMeaning
Embedded ImageThe nth of Jacquard’s (1970) nine condensed modes of IBD, described in Table 2
Embedded ImageWithout a subscript, Embedded Image is used to symbolize the coefficient of fraternity
AThe event A, typically the event of sampling some particular allele in some particular gamete
aA random variable indicating whether event A occurred, which takes on a value of 1 when event A occurs, and a value of 0 when it does not
Embedded ImageThe probability of event A
Embedded ImageThe expectation, or mean, of the random variable a. Equivalent to P(A)
Embedded ImageAn estimate of Embedded Image
Embedded ImageThe nth central moment of a, defined as Embedded Image
Embedded ImageA mixed central moment of a, b, and omitted variables, defined as Embedded Image
Embedded ImageThe inbred relatedness, which is the probability of sampling a locus where individual X is inbred and also related to individual Y
Embedded ImageThe coefficient of coancestry, or kinship, between individuals X and Y, which is the probability that an allele in individual X is IBD to an allele in individual Y. Also denoted by θ and Embedded Image in some texts
Embedded ImageThe second-order zygosity correlation of individuals X and Y, which is the probability that there are two pairs of alleles which are each IBD. Either both individuals are inbred but unrelated, or the individuals are genetically identical but not inbred
Embedded ImageThe fourth-order zygosity correlation of genotypes between individuals X and Y, which is the probability that all four alleles in the two individuals are IBD
Embedded ImageThe allele-frequency estimation error, the difference in allele frequencies between individuals X and Y
Quantitative-genetic terms
Embedded ImageThe additive genetic variation of the population
Embedded ImageThe dominance genetic variation of the population
Embedded ImageThe covariance of additive and dominance effects in inbred individuals
Embedded ImageThe variance of dominance effects in inbred individuals