Nature does not solve problems. Molecules bump into each others. There's no purpose in their doing so. There is not simple for nature and complex for us. If you want a scientific approach to complexity, you would not insert a term in the definition that reads as 'us', or 'nature', or frogs.
Alright, there is no inherent purpose (something I always say to others and here I am giving the opposite impression :) but if we agree that things 'are' because they sustain some abstract structure in some context then can't we allow saying 'to sustain' is a problem to solve ? and if the context is very diverse thus high in complexity. And as we lack information, the observed structure will elude our understanding, 'complex for us'. From my very limited point of view, I'd believe nature follow some sort of simplest path possible (~lagrangian) law, hence my 'simple for nature' expression.
Living organisms are not structures. Not sure if that's what you say, but I have heard this many times, in the context of origin of life. Where life is seen as self-replicating structures.
The complexity of a geometrical structure (like a cube, or a protein) is one thing. The complexity of a process that fulfills a function (engine of a car) is another thing. One is static, the other is dynamic. One just sits there. Like a pile of rocks. The other one takes an input and process it into an output, in a specified, repeatable manner.
A pile of rocks, in a particular context, solves the problem of surviving the surrounding conditions. Is it the simplest solution? Who cares!
DNA replication on the other hand? What did Mother Nature drink to come up with this problem and try to solve it?
That's why I added 'abstract' it's not fixed, things move underneath but the abstract properties remain.
Funny about the rock thing, I never know what to make about them, I would need to add an 'adaptability' rule to my core ones.
DNA replication did not emerge from the early organisms. Before replication, we could investigate about DNA or prototypical forms of DNA as forms of variable input transformation. This kind of meta-encoding (sorry programmer POV leaking) of input tranformation is probably not the first minimum but pressure + time pushed the versatility needs up (again programmer POV).
I'm a programmer too, but also a physicist, and it's also hard for me to read through explanations/narratives that use a lot of metaphorical language. And there's a lot of that in evolutionary narratives.
That's really a very profound way to see it! Thanks.
I'd add to that: there is even a chance (quite high btw) we are not yet seeing all the problems nature solves AND maybe we never will even though we are constantly and exponentially growing our understanding... always, forever, now.