However, life showed up on earth at a very early stage which suggest it has a relatively high probability over a planets lifespan. Without other information to go on earth is probably topical and life generally shows up within the first 500 million years watter shows up.
> However, life showed up on earth at a very early stage which suggest it has a relatively high probability over a planets lifespan.
1 - That's a good explanation. As good as any other.
2 - Alternatively, life's appearance depends on something that only existed in that short timespan (both light and a big temperature gradient at the same place is a great candidate).
3 - Or life requires some time to evolve so intelligence can only appear on planets that life was early.
4 - Or, you can mix #2 and #3 at varying amounts.
You will need a huge amount of self-replicating chromosomes between 180 and 160 basis to make up for the increased size - it's known that self replication is not common, but I don't think we know that to a 10^-22 certainty either, so all that can still be wrong.
Anyway, there isn't a lot to argue about self-replicating on that context. It means that this chromosome is able to create copies of itself in a RNA-rich ocean. It can require light for that, or a big thermal gradient, but not both. The exact conditions of the ocean are, AFAIK, unknown, but things like your example do not fit.