Natural Selection Seems Insufficient

[Jal]

You are, you just don't realize that you are.  This is apparently hidden from you.  Saying a thing is undetectable is saying that it does not interact.  

Personally, I feel that you're invoking a cloaking robe of elvenkind to protect your ideas about souls..not because it makes sense, or even makes sense in the context of your other beliefs.

Bullshit. That's a non-sequitur.  Or false dichotomy. Or some other fallacy.  "Humanly undetectable" doesn't translate to impotent. Many things were humanly indetectable until modern science.

You're underestimating God's ability to play hide and seek.

Don't overcomplicate this. God simply loves His clay dolls.