To generate these hypothetical alternative codes, we had to begin with certain assumptions about realistic restrictions under which a code would operate in a world made of DNA, RNAs and amino acids.

• 想要建立假设中的新版密码系统，我们得先根据目前已运作于DNA、RNA及胺基酸系统的遗传密码所受到的实际限制，做一些假设。