[bsder]

Life may not look like us, but it sure seems like it's going to have nucleic acids just like us.

The building blocks are extremely common, they seem to have fairly broad initial conditions, and it seems like they are practically inevitable once those conditions exist.

[pfdietz]

> it seems like they are practically inevitable once those conditions exist

Given that we have exactly one occurrence of Origin of Life, how did you conclude this? From life originating quickly on Earth once it had cooled enough? That could be explained by the conditions in which life might originate not persisting for very long after a planet forms.

[bsder]

My comment is about the building blocks.

We seem to find amino acids everywhere. It seems like once conditions exist that they can form, they DO form.

We don't have any equivalent building block which is anywhere nearly so ubiquitous.

In addition, these building blocks are reversible within 3kcal/mol. Life requires reversibility. http://wavefunction.fieldofscience.com/2008/10/unbearable-he...

We have no other building blocks with this kind of versatility. None.

So, life may not be based on DNA/RNA, but it's almost certain to be based around amino acids.

[pfdietz]

Ah, ok. You were talking about the small molecules, not life. That seems ok, although realize that the amino acids formed are a large superset of the ones life has ended up settling on. So it's conceivable another OoL event would settle on a different (if not disjoint) set.