near neutrality

Ohta T 1972 Evolutionary rate of cistrons and DNA divergence. J Mol Evol 1:150-157.

• the majority of the amino acid substitutions in evolution are the result of random fixation of nearly neutral mutations for which selection intensity fluctuates considerably but the average selection coefficient is very slightly negative

• Ohta and Kimura (1971) suggested the possibility that the majority of the amino acid substitutions in evolution are not completely neutral but are very slightly selected against during the course of their substitution by random drift

• the puzzling relationship between cistron and DNA divergences can be explained by the modified neutral drift theory
• the majority of the evolutionary amino acid substitutions in proteins are due to random genetic drift of nearly neutral mutations which have more chance of being selected against than that of being selected for during the course of their substitution in the population

• I believe that the extended form of the neutral drift theory presented in this paper will help us to understand the mechanism of protein and DNA divergence in evolution