At the end of the 1960s, two groups of scientists—Kimura (1968) and King and Jukes (1969)—independently proposed that a majority of the evolutionary changes observed in proteins were neutral.
A finais da década de 1960, dous grupos de científicos (Kimura en 1968, e King e Jukes en 1969) propuxeron independentemente que a maioría dos cambios evolutivos observados nas proteínas eran neutros.