If you are a farmer, you are concerned about a specific plot of land. Your whole world view is tied to farming how to relate to the land, how to stay in harmony with the land. It will be significantly different form a hunter who moves with the game. Related to this is also structures. Nomadic peoples build a portable dwelling they can take with them when following the game.
Farmers build more permanent, solid dwellings since they stay with their land.
In that world, man began to do things that were not in harmony with the proper way of doing things. Things were beginning to fall apart, there was alot of corruption. It got to the point where it was unbearable to live that way. The wise men came together to find a better world to live in. One bird was successful, and found a pristine world.