VARIATION IN GENETIC IDENTITY AMONG RELATIVES

Genetic identity, or genetic relatedness, among relatives, is a key co ncept in kin recognition, which in turn is important in models for inc lusive fitness and inbreeding avoidance. A mathematical definition is presented for the genetic identity based on the proportion of genome s hared identical by descent by two relatives. The method of Guo [Am J H uM Genet 1995;56:1468-1476] is used to compute the variance of the gen etic identity for various types of relationships. The method is versat ile and can handle any kind of relationship. To illustrate the method, the standard errors of the genetic identity using published human gen etic maps are computed.