What factors account for nose shape and size among different ethnicities?

What factors, environmental or otherwise, account for the many nose shapes and sizes (large, small, greek nose, roman nose, nubian nose, upturned nose, arched nose, etc... among peoples of different ethnicities?





(I asked this question yesterday as well to no avail thus far- I'm curious to see if I can catch anyone early this time who might know the answer!)
What factors account for nose shape and size among different ethnicities?
I can't account for ALL of the different types of noses. But I did see a documentary that described the differences in evolution between European and African noses. It had said that because the Europeans typically came from the north, in colder weather, they had evolved to have noses that are taller and narrower - designed to trap the cold air and and make it warmer, so as not to chill their lungs. Conversely, the Africans came from much warmer weather, and had therefore evolved noses that are flatter and wider to cool off the air before entering the lungs.
Reply:It is all to do with the privailing weather. Cold, Hot, Windy, Dry, Wet, and a conglomeration of all five. PS It' all got to do with climate and nothing at all do do with genetics.
Reply:Good you did not mention hooked nose or you might have been called an anti semite!
Reply:It's called genetics take a class on it, you'll learn much. LOL