“Concisely describe the straw man in this case.”
That antibiotic resistance genes did not exist before the human production of antibiotics. Furthermore that the discovery of antibiotic resistance prior to the manufacture of antibiotics is an argument against evolution.
“That antibiotic resistance genes did not exist before the human production of antibiotics”
Although I agree you won’t find this false argument in scientific circles, it’s very commonly believed, and widely implied, in the larger segments of society.