Lemons. He liked lemons. They made you make funny faces when you bit them, and a very, very long way in the future there was a really amazing planet where they'd evolved into people and lived in harmony with a variety of hyper-intelligent bee. Evolution. Thousands and thousands of years of tiny changes could turn little burning sparks of chemistry into people, into monsters and angels and even human beings.

Doctor Who: Keeping Up with the Joneses