For some reason this brought epigenetics to my mind. I vaguely recall reading about a study where scientists spritzed mice with lemon juice and then gave them a painful shock, so they naturally became averse to the smell of lemon juice, associating it with pain. But the eerie thing is, the descendents of the mice, several generations down the line, also had an aversion to lemon juice, though they had never been exposed to it or the shocks. They also had no contact with their ancestors, so it seems the aversion was not learned but genetically encoded.