Cosmological natural selection, also called the fecund universes, is a hypothesis proposed by Lee Smolin intended as a scientific alternative to the anthropic principle. It addresses why our universe has the particular properties that allow for complexity and life. The hypothesis suggests that a process analogous to biological natural selection applies at the grandest of scales. Smolin first proposed the idea in 1992 and summarized it in a book aimed at a lay audience called The Life of the Cosmos, published in 1997.