"As I Thessalonians 5:11 states:" "Prove all things; hold fast that which is good." "The Bible itself demands and commends a logical test of its claims.(Acts 17:11)
Creationists have a much more recent history than the Ancient Israelies. In the 1800's when Creationism was the leading theory/explaination of the day scientists actually tried impressively to fit new physical findings to the books of Moses. As the Ark got bigger and bigger to hold all the new species it sunk. But those scientists unlike the 'got-ya' Creationists of today actually had a scientific theory of origins to defend.
Genesis never said that the life that went into the ark was adults in age. And to be precise, Genesis never said that the ark carried each species, but each kind. The classification by species is but a few hundered years old.