Genesis describes pairs of each of the animals, but seven of certain
animals. These were the ceremonially clean animals which Noah and his
family were to eat while on the ark. These animals are domesticated ones.
Genesis 7:1,2 says to take two of each animal, except seven of each clean
animal. I admit I am guessing that he was to take seven of each of the
“clean” animals for food, but that seems like a reasonable explanation of
why he did it. Either way, there certainly is no contradiction here.

John Oakes, Ph.D.