Its effect is physical. But natural selection itself would have to be understood as a type of cause. Causes are not physical things, though their effects often are.
I think you conflate cause and effect here. But they are not the same thing, epistemologically speaking.
What is causing the natural selection in the example I mentioned? It was a physical cause - causing physical death of those variations that the antibiotic could physically bind to.
What was the effect of the natural selection I mentioned? Only those variations that the antibiotic could not physically bind to were left alive.
Full retreat into semantics and epistemology is not answering my rather simple question.
Absent any knowledge on your part of what DNA is or what it does - I cannot take at face value any assertion that you make about it not being necessary and sufficient to its assigned task.
Absent ANY description of the physical mechanism of the evolution you say you believe in, I must conclude that you have no real intellectual curiosity on this subject to go along with your almost complete lack of knowledge.
So you say you believe in evolution, and that there is some underlying physical mechanism - but you have no idea how to describe it without it being a “Darwinist” argument.
That right there is real amusing!