Few of the cultural traditions and rules为主语,that today allow us to deal with dense populations是定语从句,修饰the cultural traditions and rules,existed是谓语,for these people是状语,
accustomed to household autonomy and the ability to move around the landscape almost at will是定语,修饰people,其中household autonomy and the ability to move around the landscape almost at will是介词to的并列宾语