遗传密码的起源和进化：宇宙之谜
Origin and evolution of the genetic code: The universal enigma
摘要：
遗传密码几乎是通用的，并且标准密码子表中密码子的排列是高度非随机的。关于密码起源和进化的三个主要概念是立体化学理论、协同进化理论和误差最小化理论。这些理论并不相互排斥，也与冻结事故假说相容。对编码的结构和可能的进化轨迹的数学分析表明，它对翻译错误具有高度鲁棒性，但存在大量更鲁棒的编码，因此标准编码可能通过短序列的密码子序列重排从随机编码进化而来。因此，导致标准编码的大部分进化可以解释为冷冻事故与翻译错误最小化选择的组合，尽管不能排除编码与代谢途径和/或氨基酸和核苷酸三联体之间弱亲和力的共同进化的贡献。然而，这种情况下的代码演变是基于正式的计划，其相关性的实际原始的演变是不确定的，所以在解释上要谨慎。只有结合编码原则本身和翻译系统的演变的可信情景，才有可能真正理解代码的起源和演变。
英文摘要：
The genetic code is nearly universal, and the arrangement of the codons in the standard codon table is highly non-random. The three main concepts on origin and evolution of the code are the stereochemical theory; the coevolution theory; and the error minimization theory. These theories are not mutually exclusive and are also compatible with the frozen accident hypothesis. Mathematical analysis of the structure and possible evolutionary trajectories of the code shows that it is highly robust to translational error but there is a huge number of more robust codes, so that the standard code potentially could evolve from a random code via a short sequence of codon series reassignments. Thus, much of the evolution that led to the standard code can be interpreted as a combination of frozen accident with selection for translational error minimization although contributions from coevolution of the code with metabolic pathways and/or weak affinities between amino acids and nucleotide triplets cannot be ruled out. However, such scenarios for the code evolution are based on formal schemes whose relevance to the actual primordial evolution is uncertain, so much caution in interpretation is necessary. A real understanding of the code's origin and evolution is likely to be attainable only in conjunction with a credible scenario for the evolution of the coding principle itself and the translation system.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
