Where do fruit flies come from?!

While riding the train into San Francisco the other day, I had a conversation with an older gentleman that I was drawing. I try to be discreet while drawing people on the train because I know that this might bother some people, and I don’t want to bring too much attention to myself.

While I was drawing this man, he took notice and even held still to pose for me. He asked me if I went to college to learn how to draw. And I answered that I did, but that I have always loved to draw. He then said-

“So, college boy…. where do fruit flies come from?”

I was caught off guard by this, and fumbled in my reply- “Uh…from the fruit when it gets old…um, I don’t know…”

He then said- “Oh, so you have been to graduate school but don’t know where fruit flies come from…I see…”

A little flustered, I replied- “Well, where do fruit flies come from?”

As he exited the train, he said- “Go find out.”

Anyone reading this article know where fruit flies come from?