Boy (extra politely): Excuse me, Mom. Do zombies have skeletons?
Mom: Yeah, because they are people that were bitten by zombies, died, and then became zombies themselves. People have skeletons, so zombies have skeletons.
Boy (somewhat exasperated): Yeah, I know that. I mean, the first zombie. Did he have a skeleton? The first zombie wasn't bitten by another zombie.
Mom: Well, I think the first zombie got a virus, died, and then became a zombie and ate brains. So, that person would have a skeleton too. (As a panicked afterthought) But don't worry, that's just a make-believe virus, not like ones you and I get.
Boy: Okay, so the first zombie had a skeleton. Thanks.
I hope he won't be disappointed if they don't cover Zombie Anatomy in school. And I hope his school won't be disappointed if he wants them to.