Under genetic drift and in the absence of selection, the Fst values are expected to be equal at all loci, and heterogeneity among such values is considered as an evidence for different systematic pressures affecting the different genetic systems considered. A two-step test is here proposed. Fst, values at various loci are classified into two nonarbitrary groups through the analysis of the association between pairs of genetic and environmental variables; the heterogeneity is then assessed by Wilcoxon's two-sample test. Estimation of the theoretical variance of Fst, which causes major shortcomings in the test proposed by Lewontin and Krakauer'in 1973, is thus avoided. © 1985 S. Karger AG, Basel.
A two–step test for the heterogeneity of Fst values at different loci.
BARBUJANI, Guido
1985
Abstract
Under genetic drift and in the absence of selection, the Fst values are expected to be equal at all loci, and heterogeneity among such values is considered as an evidence for different systematic pressures affecting the different genetic systems considered. A two-step test is here proposed. Fst, values at various loci are classified into two nonarbitrary groups through the analysis of the association between pairs of genetic and environmental variables; the heterogeneity is then assessed by Wilcoxon's two-sample test. Estimation of the theoretical variance of Fst, which causes major shortcomings in the test proposed by Lewontin and Krakauer'in 1973, is thus avoided. © 1985 S. Karger AG, Basel.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
