Lack of evidence for segregation of a single dominant major gene as the cause of the difference in egg weight between two highly inbred lines of chickens.

Data on egg weight from experimental crosses with two inbred lines of chickens suggested evidence for segregation of a single dominant major gene. Because the data could not be transformed to satisfy normality and homoscedasticity conditions, the non-parametric test of Elston and the graphical approach used by Stolk et al. were applied. Due to a bad fit of the backcross B2 (P2×F1) and the F2 groups, both methods reject the hypothesis of a dominant major gene as the the only cause of the differences in egg weight between the six genetic groups involved.