Power curves of the test statistics F4,a and F4,ad against the heritability h2 at a 0.05 significance level. (A and C) The curves are plotted for a dominant mode of inheritance a = d = 1.0; (B and D) the curves are plotted for a recessive mode of inheritance a = 1.0, d = −0.5. F4,a and F4,ad are calculated when marker A has four equal frequency alleles; i.e., . The measures of LD are given as follows: (A and B) (C and D) . The other parameters are q1 = 0.50 and N = 250.