“Imagine that the history of the world is represented by a clockface, say, then the the appearance of blue-green bacteria in the record happened at about two oclock, while invertebrates appeared at about ten oclock, and mankind, like Cinderella suddenly recalling the end of the ball, at about one minute to midnight. I do not know whether such images are useful other than as encyclopaedia illustrations.”

—Richard Fortey, Life: A Natural History of the First Four Billion Years of Life on Earth, 1998.