[js1138]

If a bacterium gets a less than life-threatening dose of poison, what's so unreasonable about the fact that it develops a further immunity against said poison? This is not mutation.

Ask a biologist this question and get back with me. I don't have the references at hand to counter you, but I'm sure you are wrong about this. Bacteria re clones. Antibiotic resistence does require mutation.

I'll wait for a reference refuting this.

[Frumious Bandersnatch]

Antibiotic resistence does require mutation.

Again, not necessarily.  Try "immune system."  All organisms have them.