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来源：雅诚德英语网
In 1890 he proposed that evolution was irreversible: that 'an organism is unable to return, even partially, to a previous stage already realised in the ranks of its ancestors'.
1890年，他提出进化是不可逆转的：“一个有机体无法回到其祖先先前到达的阶段，即使是部分逆转，也不可能。”