This vignette demonstrates how to quantify relatedness using two
functions from the BGmisc
package: -
calculateRelatedness
computes the relatedness coefficient
based on known genealogical structure, and -
inferRelatedness
infers the relatedness coefficient from
observed phenotypic correlations under a fixed ACE model.
The relatedness coefficient \(r\) indexes the proportion of alleles shared identically by descent (IBD) between two individuals. This value ranges from 0 (no shared alleles by descent) to 1 (a perfect genetic match, which occurs when comparing an individual to themselves, their identical twin, or their clone). Values can be interpreted in the context of standard relationships: e.g., full siblings are expected to have \(r = 0.5\), half siblings \(r = 0.25\), and first cousins \(r = 0.125\).