Dictionary Meaning and Definition on 'Relatedness'
n : a particular manner of connectedness; "the relatedness of
all living things" [ant: unrelatedness]
- Relatedness \Re*lat"ed*ness\, n.
The state or condition of being related; relationship;
affinity. [R.] --Emerson.
Wikipedia Meaning and Definition on 'Relatedness'
In population genetics, Sewall Wright's coefficient of relationship or coefficient of relatedness or relatedness or r is defined as 2 times the Coefficient of Inbreeding. The 'Coefficient of Inbreeding' (or: coefficient of kinship) is defined as the probability that the alleles at a particular locus chosen at random from two individuals are identical by descent.
The coefficient of relationship between parent and offspring is 0.5, meaning half of the offspring's genome comes from that parent. Or, more precisely said, half the genes are identical by descent.
Some other relatedness examples: (assuming no consanguinity of the parents, for diploid species unless noted otherwise)
Some of these definitions of r are tricky to calculate. For example, consider that you are one of a family of half brothers with the same mother but different fathers. Call rm the coefficient of matrilineal relatedness and call rp the coefficient of patrilineal relatedness. What is the coefficient of relatedness to each of your half brothers?[See more about Relatedness at Dictionary 3.0 Encyclopedia]