A comparison of gene flow estimates based on private allele frequencies.

The frequency of private alleles is often used to assess the amount of gene flow (Nm) between populations, with the equations proposed by SLATKIN (1985b) and by SLATKIN and BARTON (1989). Although these equations express the same relationship, they may yield different estimates of gene flow for the same data. These differences increase with decreasing frequencies of private alleles. Comparisons of Nm estimates, based on different equations can therefore be misleading. It is advisable to use these equations method only to distinguish between Nm > 1 and Nm < 1.