A restriction on. the space of genetic relationships

Abstract

For non-inbred pairs of relatives it is possible for all 4 cross-parental kinship coefficients to be non-zero, and hence the expression often assumed for the correlation between such relatives is not completely general. A restriction on the space of attainable Cotterman coefficients for a relationship between 2 arbitrary non-inbred relatives is derived. This restriction implies that the form of the expression for the correlation is in fact general, although the components cannot always be interpreted as parental kinships.