Good to see this being done.
Another step on the path.
And evolution is really complex.
It starts with a simple idea, replication with slight variation and differential survival acting as a filter to drive selection between variants in different contexts.
In one sense it always works through survival of the replicator, and in another sense, replicators can form associations at various strengths, and if the strength of the grouping is at least as strong as the strength of some selection pressure, there can be evolution at the level of that group.
Thus we see alleles, viruses, cells, bodies, families, and larger collections of groups right up to ecosystem level.
The process can be recursive at every level, thus there can be pressure for rapid variation in parts of the genome responsible for immune system variation, while being very conservative over other areas (like cytochrome C).
Cellular chemistry is very much based on RNA, with RNAs making up the ribosome, and all of the connecting bits of the codon reading system. I strongly suspect we are going to find quite a few more levels of RNA functionality, and this is just another step on that path.
When you think about it from a cell’s eye perspective (given that when a cell divides the two parts are essentially indistinguishable from a genetic perspective), all cellular life alive today is essentially 4 billion years old. The default mode for cellular life is indefinite life in this sense.