The scene of a frozen accident

It has been suggested that in vitro selection experiments can provide infor mation not only on what might have occurred during the evolution of the RNA world, but can in fact yield insights into particular features of the RNA world. In particular, it has been suggested that the sequences of anti-amin o acid aptamers can provide clues to the origin of the genetic code, and th at there is a statistically significant association between motifs found in aptamers and codons. We argue that the suggested connections between moder n motifs and ancient sequences are logically tenuous, and show that there i s no statistically meaningful association between motifs found in aptamers and codons.