I will cause it to rain upon the earth forty days and forty nights; and every living substance that I have made will I destroy from off the face of the earth. (Genesis 7:4)
One of the odd things about the story of the Biblical flood is this idea of all the world’s land animals coming to the Ark, and then returning to their locations afterwards. Now, to understand why this is strange, consider the fact that animals in the Americas would have a hard time walking to the Middle East. Even if we presumed an ice bridge across the Bering Strait, it would be difficult for cold blooded animals to travel from the Ark back the the Americas. This problem affects snakes, lizards, spiders (including tarantulas), scorpions, insects, and all kinds of other tropical and desert dwelling animals. Most of those animals aren’t very capable of traversing the arctic.
I mentioned this to one creationist, and he gave the explanation that maybe (post-flood) people brought them back to the Americas on their boats. That explanation didn’t seem very good. First of all, are we supposed to believe that humans brought animals (snakes, lizards, tarantulas, and scorpions) – some of them poisonous – thousands of miles on their boats? Second, those animals are not found on the (intermediate) Pacific Islands, which they would surely inhabit if brought there on a journey from the Old World to the New World.
Additionally, once the animals left the Ark, there are a lot of nearby regions they could inhabit, but didn’t. For example, all varieties of rattlesnakes are found in the Americas (33 species, and numerous subspecies). There are none in the Old World – despite the fact that there are regions similar to the American deserts – the Sahara, the Middle East, the Gobi Desert, etc. Llamas fit this same pattern – found in the New World, but not in the Old World. The Caucus (where the Ark supposedly landed) and Himalaya mountains have different species than the Rocky Mountains and Andes. Why didn’t some of the Rocky Mountain species stick around in the Caucus Mountains – they were already there the minute they stepped off the Ark. Similarly, the species in the South American tropics aren’t found in Old World tropics (Southeast Asia and Africa), and vice-versa. For example, New World cats and monkeys are different species than Old World cats and monkeys. Theoretically, with the movement of creatures caused by the global flood, one could find the same species living in distant places. Somehow, we don’t.
I suppose the best explanation that a creationist could give to all this is simply “it’s a miracle”. Miracles are pretty flexible things – able to fix all kinds of problems. In fact, there’s no problem a miracle can’t fix. Although, one has to wonder – with God bringing animals halfway around the world (miracle #1), keeping them alive in climates where they can’t normally survive (miracle #2), providing them with food in cases were their regular diet was not available / making them not need food (miracle #3), producing land bridges over water (e.g. between Australia and Southeast Asia, Madagascar and Africa) (miracle #4), producing massive quantities of water to drown everything (miracle #5), making sure that freshwater fish and saltwater fish can all survive in the same common floodwater (miracle #6), making sure they all go back to where they came from without stopping in similar geographical areas (miracle #7), and repeating miracles #1, #2, #3, #4 during the return trip – why did God use a flood and a man-made Ark? Seems like it would’ve been a lot easier to have all the bad humans simply disappear in the middle of the night, send a local flood, or miraculously protect all the animals from drowning (just like how He kept all the freshwater and saltwater fish alive in common floodwaters).
Related Topic: The Creation Museum Teaches Super-Evolution (i.e. super-fast diversification and speciation after the flood) in order to explain how all those species could fit inside the Ark. (Which, by the way, super-speciation adds one more miracle God has to perform.) I find it particularly ironic that creationists use super-fast speciation to fix the Ark’s size problem, and meanwhile, other creationists attempt to attack evolution by claiming there are few or no examples of speciation – and calling it a “key problem” for evolution.