A question about the great flood...?

In the epic of Gilgamesh, Utnapishtim survived a great flood with his family and representatives of the animals on earth. He is warned about the flood by a god about the flood, and builds an Ark to survive it. His Ark comes to rest on a mountain, and he releases birds to see if there is dry land. Does any of this sound familiar to Christians? is it possible that much of the Bible was taken from the mythology that surrounded the Jew's when they were in Babylon? could other parts (the description of the heavens and earth are remarkably similar) have been lifted from mesopotamian myth? since through archaeology it has been determined that these civilizations were around before ancient Israel, should we be following their belief system? why should we cast these off as "myth" and the Bible as "truth"?