Kimura examined the rate of evolutionary change of proteins and proposed the neutral theory of molecular evolution in 1968. His theory – which held that evolutionary changes at the molecular level are caused not by natural selection, but by random genetic drift – provided a good explanation for the genetic variation that researchers had discovered.
我已故的同事木村本雄最先提出了支撑上述理论的证据，他假定存在对个体既非有利亦非有害的中性基因突变，因此也不受自然选择的管辖。木村研究了蛋白质进化率，并于1968年提出了分子进化的中性学说。他的理论认为导致分子水平进化改变的不是自然选择而是随机的遗传漂变，他的理论很好地解释了研究人员发现的遗传变异现象。