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danby t1_iurb7az wrote

> Assuming the most conserved are the oldest, candidates for 'oldest sequence' are the RNA sequences for the 16S and 23S ribosomal subcomponents, plus assorted tRNA sequences (all involved in converting RNA into protein),

Interestingly the emergence of a unified means of RNA translation is likely what drove the emergence of genome based organisms (rather than the prior progenotes) and in turn gave rise to the Last Universal Common Ancestor of all life (circa 3.6-3.9 bya). Which is why tRNA and ribosome sequences are among the most ancient sequences we have.

Here's a very nice paper summarising what we know about this molecular evolution and

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008548/

And my favourite Carl Woese paper on the subject

https://pubmed.ncbi.nlm.nih.gov/9618502/

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