As much as I hate to admit it, Jerry is a member of the human race. He has 20 digits, can count to 10, and his knuckles don't drag on the ground (even if here were skinny). He does sort of have that cromagnon facial features and hairdo, but it can speak and knows how to climb a ladder. And you'll never see him with a chicken bone through his septum.
It's very possible that if he ever loses his virginity (to somebody other than his brothers) and actually manages to procreate, that his children will be less than human - provided they don't commit suicide in the womb.
-sw