The original data of Nilsson-Ehle
experiment in wheat were analyzed with existent genetic knowledge. It indicated
that the core of polygenic hypothesis from this experiment was that a character
similarity produced by additive effect of multiple genes was the basis of
continuous variation. Its precondition was for effective genes to have equal effect,
to show merodominance and binomial distribution
and
to inherit independently.
In fact, quantitative characters were determined by many genes with different
property, effect and behavior. So it was difficult to solve all problems of
continuous variation by the aid of polygenic hypothesis. The researchers should
seek new ways. With Mendelian group as research object and by means of Lyapunov
central limit theorem it was proved that both genotypic value G and the
environmental effect in a niche E were subordinated to the normal distribution
and respectively. According to additivity of the normal distribution the
phenotype P = G + E also obeyed the normal distribution P = G + E ~
and
quantitative characters showed continuous variation, whether or not the linkage
was presented, whether or not every gene effect was equal, whether or not there
were dominance and what kind of dominance between alleles. Moreover it was
discussed that the quantitative characters in self-fertilized organism and
clone were submitted to the normal distribution and presented continuous
variation too.