For a long time, since I learned about how evolution works at the gene level, I’ve been bedazzled by sharks. Here is a configuration of genes which has reached such a sweet spot in the eyes of evolution that it has cruised mostly uncharged (modulo the shrinking due to change in oxygen composition) for hundreds of millions of years. Then I learned about the code of RNA (credit to Deutsch I think in his treatment of evolution in Fabric or maybe it was Beginning, I don’t recall) and my mind was blown! The actual knowledge encoded in the RNA sequence—†not the physical stuff; but the precise coded sequence—required for replication is actually quite ubiquitous across species and unchanged on timescales vastly larger than I had previously fathomed, mountains look like sand castles and sharks are brand new in the eyes of the code of RNA. This is only an analogy; but it felt like how Unix works: RNA is like the tiny kernel which has spread everywhere due to being tiny and good enough to solve the problem and therefore difficult to replace. Anyways, this is only a day dream since I’m not really in the weeds; but I wonder if you can correct any of my misconceptions. Like: RNA is like code for DNA replication, is it sort of like low-level machinery for life? Has the precise RNA code survived a really long time and it’s sort of like an old operating system which just keeps humming in the background? And it is older than sharks right? Any other cool stuff to recommend pursuing for someone like me who really loves evolution; but is just a layperson?

†one note about my em dashes: I am a real person who thinks evolution AND em dashes are cool and for a total aside: it’s such a bummer people think I’m a bot just because I like tinkering w/ f* punctuation marks.

Does the current SOTA believe that it's most likely that life originated on Earth? I know there are some theories that at least one of the critical building blocks was delivered via asteroid or other extra-terrestrial process.