What a dull universe it would be if everything in it conformed to our expectations, if it held nothing to surprise or baffle us or confound our common sense. A century ago no one foresaw the existence of black holes, an expanding universe, oceans on Jupiter's moons, or DNA. What could be more enriching than to know that we share a common origin with all living things, that we are kin to chimpanzees, redwoods and mollusks? And isn't it a source of wonder to realize that the iron in our blood and the calcium in our bones were created in the bellies of supernovas?
An enormous amount of scientific language is metaphorical. We talk about a genetic code, where code originally meant a cipher; we talk about the solar system model of the atom as though the atom were like a sun and moon and planets.
Human evolution, at first, seems extraordinary. How could the process that gave rise to slugs and oak trees and fish produce a creature that can fly to the moon and invent the Internet and cross the ocean in boats?
