Commentary for Leviticus 11:7

והוא גדה לא יגר, but it does not chew the cud, etc. The Torah uses these words as a condition, i.e. as long as the pig has not reverted to chewing the cud it may not be eaten. In the future, when it undergoes evolutionary changes so that it will become a ruminant, it will again be fit to be eaten by Jews. It is not the Torah which will adapt to "realities," but "reality" which will adapt to Torah; the laws of the Torah are immutable, the nature of the pig is not.