A Recipe to Evolve Complex Life Chemically on Earth

Sequences of tRNAs are highly patterned in easily identifiable RNA repeats and RNA inverted repeats (stem-loop-stems). Because of patterning, the multi-step evolution of tRNA can be described in remarkable detail.

To evolve life on Earth or another planet or the moon requires the evolution of tRNA or a tRNA-like molecule to act as a genetic adapter. To replace tRNA with an alternate or improved genetic adapter is a remarkably challenging problem, indicating strong chemical selection of tRNA precursors in pre-life.

The genetic code, translation systems, and first proteins coevolved with tRNAomes (all of the tRNAs of an organism). Because the tRNA sequence can be separated into component parts, a simple pathway for chemical evolution of life and genetic coding can be described in sufficient detail to allow the assembly of a living entity in laboratories.

A Recipe to Evolve Complex Life Chemically on Earth, Genes (Basel) (open access)

Astrobiology