Eukaryotes versus prokaryotes: an estimate of evolutionary distance.

The divergence of nucleated organisms and bacteria was 2.6 times more remote in evolution than the divergences of the nucleated organisms into sparate kingdoms, as evidenced by genetic changes in cytochrome c and transfer RNA. The development of the genetic code through the differentiation of transfer RNA's for different amino acids was still more remote in evolution. The overall states of transfer RNA evolution in bacteria and nucleated organisms were comparable.