Nothing here that hasn't been thought of before, but did you ever consider that every great civilization in the history of man has been based on the cultivation of a starch crop?  Africa raised barey in the North and milo and yams in the South, Europe grew wheat and rye, Asia grew rice, Polynesia raised kalo and breadfruit, South America grew sweet potatos, Central America raised corn, and so on.  All those crops have moved around the globe in the last few hundred years.  We still rely on starch crops for the basis of our food, and if there is a food crisis in the future the protein crops will give way to starch if it becomes a matter of survival.  Like I said, nothing new, but something to ponder on a Sunday morning.