Jews and Muslims prohibit pork. The Bible says of pigs: “of their flesh you shall not eat and their carcasses you shall not touch; they are unclean… .” The Qur’an says: “These things only has He forbidden you: carrion, blood and the flesh of swine.” Since both religions permit other meats, one taboo theory is pork was “unwholesome” because it sickened people. Science later confirmed undercooked pork purveys trichinosis. Since this doesn’t excuse fully cooked pork, another rationale is pigs are filthy creatures that wallow in mud and eat excrement. But this is reactive behavior to adverse conditions humans force on them. Pigs have no sweat glands so naturally live in densely shaded forests. The theory also ignores that dogs, camels and chickens will resort to eating dung, yet their meat is okay to eat.
Logically, pigs are unsuited to the hot, treeless Middle East. They’re impossible to herd and compete with humans for the same foods, consuming more per pound than cows or sheep. Thus the discovery that keeping pigs was not economical, ecological or efficient became a ban on eating them.