But he thinks it can only go backward when the evolution of the trait is simple, like when a single mutation is involved.

但是他认为只有在新特征的进化是非常简单的情况下才可以逆转，例如只有一个位点发生突变。

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The single mutation-at-a-time view would be like hoping you hit the Pick 4 lottery by getting one number a day for four days.

用四选一的彩票游戏打个比方。 单位点突变就类似四天当中每天都买4个号码中的一个，结果可想而知，都没中。

youdao

A single mutation, a different sequence in the DNA, causes the ribosome to use a different amino acid when it builds the lysozyme molecule.

单一突变，dna序列发生变化，会造成核糖体在构建溶解酵素分子时使用不同的氨基酸。

youdao

Beachy has turned normal prostate cells cancerous with a single mutation in Sonic hedgehog.

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The bad news: A Harvard University team discovered that the virus was able to outsmart another AIDS vaccine with a single mutation.

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To fix these problems, Ketek grapples onto a second spot inside the bacteria, so bacteria can no longer escape the drug with a single mutation.

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