Noah's Ark, or Noah's flood, is one of the more charming myths in the Bible, and a popular bedtime story for Christian Children. Like all bedtime stories, there is little rational thought in the story. For example, all plant life would have been wiped out as well? And if we're descended from Noah, then how is it we have such a wide range of skin color? Are we the result of many generations of inbreeding (well, that could explain Andrew Schlafly and Creationists.
In this story, God believed the world had become corrupt and told Noah that he was going to destroy the world in a flood. God warned Noah that there would be a devastating flood and instructed him to build a vessel (called Noah's Ark) for the purpose of saving his family and representatives of every animal species. The ark somehow could house his family and two of every animal (even useless one like stink beetles and dodos). A great Waterworld-esque flood covered the world and then subsided.
The story’s charming if one is willing to overlook the fact that the story maintains that God killed every man, woman and child on Earth, with the exception of Noah's family, and every animal that wasn't taken on board the Ark. Incidentally, Christians also believe that God is loving, see Problem of Evil.
The story is better seen as a good example of Biblical propaganda designed to scare young children and gullible conservatives into believing in a vengeful God.
It is doubtful a wooden vessel of that size would have been seaworthy given the technology of the time, and more doubtful that Noah's family could have rounded up two of every species living at the time (the beetle and ant species would have been particularly difficult). What did Noah and his family do with the various bacteria that cause diseases? Collecting and storing the amount of food required would have been equally difficult, and it is doubtful there would have been room for so many animals and their food. Then, of course, there is the matter of waste removal and the fact that Noah was a senior citizen. Did Noah leave the dirty work to his sons and their wives?
Noah would have had to have sailed around the world to drop off animals in the correct locations, such as Polar bears in the Arctic, penguins in the Antarctic, however, the habitats that these animals live in would probably have been destroyed. Noah also had to stop the starving carnivorous beasts from eating all the other animals, presumably by feeding them roast potatoes. However, the real problems for Noah would have started when he finally got to go home then he would have had to plant crops and repatriate the earth.
Arguments for the flood
Young-earth creationists insist that there were dinosaurs on the Ark, which may explain why certain species became extinct. One wonders what it was like to share a confined space with a Tyrannosaurus Rex! They also make spurious claims as evidence of the story, such as the kooky idea that there happens to be a limestone layer on every mountain no matter the altitude. As the flood only lasted a year, a limestone layer would not have had time to accumulate. Finally, Noah's Flood is invoked by Young Earthers to explain such geological marvels as the Grand Canyon and fossil layers. If there hadn't been a flood, they would have had to invent one.
Some creationists use this to explain how the fossil record contains many animals and plants that are no longer around today. But such explanations have a few flaws, one being the number of extinct sea creatures in the fossil record, another being that the fossil record shows a complex history of creatures appearing and then disappearing over more than a hundred million years.
Creationists further argue that because so many disparate cultures have flood stories, the stories ultimately are from the original flood. Water happens to be scary to people, and since all continents bordered water and have rain floods, all cultures should have flood stories. Conservapedia claims that in most flood stories, there is great similarity in that they have an angry God as a cause, people surviving by floatation of by climbing a mountain, with a single-family surviving. These details are a natural choice for our ancestral cultures on the six continents. There is little way to survive a flood except via floatation or high ground. The flood can't kill everyone (where would we be), but the legend must be as exciting as possible, so the minimum unit of reproduction, a family, survives. The flood is caused by a God because scientific meteorology wasn't popular 5,000 years ago. And that God was angry, why else kill off almost everyone? An alternate explanation of the similar stories is that the overall concept of "Angry God Floods World" dates back to when everyone was in Africa.
There is scientific evidence that a devastating local flood probably occurred in the region the writers of the Bible would have considered "the world". Written works such as the Epic of Gilgamesh, as well as numerous oral traditions, also refer to a similar flood. Stories also tend to get distorted over time.