Observations on the normal distribution of quantitative traits

Two experiments are assumed, which show that group equal assortment of genes produces a centripetal effect and group unequal assortment of genes produces a centrifugal effect. The normal distribution of quantitative traits is intermediate between group equal assortment of genes and group unequal assortment of genes, which means the reduction division and the assortment of genes are relatively equal (not completely equal). From the experiments, we find that individual equal assortment of genes produces a centrifugal effect and the individual unequal assortment of genes produces a centripetal effect. The centrifugal effect of individual equal assortment of genes leads to the result that the F2 generation is considerably more variable than the F1 in the Emerson-East experiment with sweet corn (1). Group assortment interacts with individual assortment. The centrifugal effect interacts with the centripetal effect. These interactions affect the stability of inheritance and variation.