INVARIANT PER-GENOME MUTATION RATES

20世纪60年代末，几个实验室的数据显示， 表明微生物表现出恒定的正向突变率， 每个基因组每次复制0.003;基因组大小变化约1000倍， 因此，每次复制每个碱基对的突变率与此相反。 这 观察表明，突变率已经进化到一个最佳状态， 在不同的生物体中是惊人的稳定。 此后该 已公布的数据库已改善了许多生物体和不变性 每个基因组的突变率似乎不仅仍然是常态， 从含有单链DNA的噬菌体一直延伸到 微生物真核生物 然而，RNA病毒和后生动物似乎拥有 突变率与基于DNA的微生物完全不同

In the late 1960s the then-available data from several laboratories suggested that microbes exhibited a constant forward mutation rate of about 0.003 per genome per replication; genome sizes varied by about 1000-fold, and so, inversely did mutation rates per base pair per replication. This observation suggested that mutation rates had evolved to an optimum that was surprisingly constant among diverse organisms. Since then, the published data base has improved for many organisms and the invariance of per-genome mutation rates appears not only still to be the norm, but to extend all the way from a bacteriophage containing single-stranded DNA to microbial eukaryotes. However, RNA viruses and metazoans appear to possess mutation rates quite different from those of DNA-based microbe