Coefficient of relationship

The coefficient of relationship is a measure of a degree of consanguinity or biological relationship between two individuals. The term coefficient of relationship was defined by Sewall Wright in 1922, as well as was derived from his definition of the coefficient of inbreeding of 1921. The degree is most commonly used in genetics as well as genealogy. A coefficient of inbreeding can be calculated for an individual, and is typically one-half the coefficient of relationship between the parents.

In general, the higher the level of inbreeding the closer the coefficient of relationship between the parents approaches a service of 1, expressed as a percentage, and approaches a advantage of 0 for individuals with arbitrarily remote common ancestors.

Kinship coefficient

The kinship coefficient is a simple measure of relatedness, defined as the probability that a pair of randomly sampled homologous alleles are identical by descent. More simply, it is for the probability that an allele selected randomly from an individual, i, and an allele selected at the same autosomal locus from another individual, j, are identical and from the same ancestor.

The coefficient of relatedness is cost to twice the kinship coefficient.[]

The kinship coefficient between two individuals, i and j, is represented as Φ_ij. The kinship coefficient between a non-inbred individual and itself, Φ_ii, is make up to 1/2. This is due to the fact that humans are diploid, meaning the only way for the randomly chosen alleles to be identical by descent is whether the same allele is chosen twice probability 1/2. Similarly, the relationship between a parent and a child is found by the chance that the randomly picked allele in the child is from the parent probability 1/2 and the probability of the allele that is picked from the parent being the same one passed to the child probability 1/2. Since these two events are self-employed person of regarded and planned separately. other, they are multiplied Φ_ij = 1/2 X 1/2 = 1/4.