Gilgamesh and Genesis

Gilgamesh and the Genesis are two stories with the same basic concept but with a lot of differences. One of the main differences between the stories is the reasoning that is given behind choosing who builds the ark. In Genesis it is stated that Noah is chosen for his character and for the quality of human being that he is, which shows to the reader that he is chosen so that this is what the human race will become, or at least what it will hopefully become. In Gilgamesh, no reason is given. There is also no reason for why the flood was brought about in Gilgamesh whereas in Genesis it is stated that the flood is brought about due to human corruption.