I figured that anyone who took the book literally would wonder how that worked. My roommate used to be very religious, right up to freshman year of college when he was going to church twice a week and a couple bible meetings a week as well. Then he became a religion major, exposed himself to other religions of the world, and read the bible in more detail. He couldn't stand when people took the bible literally, given all the discrepancies.

And the size of the ark thing was something my college bio teacher once used to try to open one of his student's mind to at least considering the possibility of evolution.