They get stronger because they mutate to fight back
I never meant evolution, or to spark a debate about it. They fucking get stronger the more poison there is, maybe something whacky happens to them
That’s not how evolution works. A species evolves to get stronger in battle if the weak ones die in battle. A species evolves stronger lungs if the weak ones die of lung cancer. Dying of lung cancer doesn’t make a species better fighters.
Pollution makes their species stronger; this doesn’t imply an individual preference.
Idiots walking off cliffs doesn’t make the survivors like cliffs; it teaches them to avoid them.
That said, evolution can be a real crap shoot, and you never know what sort of perverse effects you’ll get: like us loving sugar so much we eat ourselves into diabetes.