Shared allele distance (Chakraborty and Jin, 1993) [Jin, L. 93]

between individuals:
D SA I = 1 P SA I , with P SA I = j r S 2r P_{SA_{I}}={sum ^{r}_{j}S} over {2r}
where the number of shared alleles S is sumed over all loci r.
between populations:
D SA B = 1 2 P ˉ SA B P ˉ SA X + P ˉ SA Y D_{SA_{B}}=1-{2{bar{P}}_{SA_{B}}}over{{bar{P}}_{SA_{X}}+{bar{P}}_{SA_{Y}}}
where the average proportion of shared alleles between and within populations X and Y ( P ˉ SA B , P ˉ SA X , P ˉ SA Y respectively) is computed overall possible combinations of individuals sampled.