Once the nucleic acid-amino acid operating system came into existence it could never be "fixed" into anything else by evolution, because the immediate consequences would have been so serious.

一旦核酸-蛋白质操作系统形成，就不可能通过进化来“修补”成其他的系统，因为这种“修补”的后果会十分严重。

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If protein evolution is due in large part to slightly deleterious amino acid substitutions, then the rate of evolution should be greater in proteins that contribute less to individual fitness.

分子演化被认为在很大程度上是由稍微有害的氨基酸取代的传播驱动的。

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Differences were discovered between mammoth and African elephant in amino-acid positions that are otherwise invariant over several billion years of combined mammalian evolution.

中氨基酸的位置，否则不变的联合哺乳动物进化的数十亿年的庞大和非洲象之间的差异被发现。

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