Links |
|---|
| email: Comments? Questions? Discussion?
Formulas for paternity situations Posers in forensic mathematics Go to home page of Charles H. Brenner |
The formulas below were derived with the help of the Symbolic iKnship Program
The triple proportion F:H:U is listed, where F, H, and U are the likelihoods of the genetic types assuming full-shipship*, half-sibship, and unrelated respectively.
From these proportions all likelihood ratios can quickly be written. For example, the likelihood ratio comparing full to half-sibship would be F/H.
| Children share two alleles (both are pq) | (1+p+q+2pq) : (p+q+4pq) : 8pq |
| Share two alleles doubly (both are pp) | (1+p)2 : 2p(1+p) : (2p)2 |
| Share one allele doubly (they are pp and pq) note | (1+p) : (1+2p) : 4p |
| Share one allele (both heterozygous, pq and pr) note | (1+2p) : (1+4p) : 8p |
| Share no alleles (pq or pp vs. rs or rr) | 1 : 2 : 4 |