We are all familiar with the popular idea that strange alien life is wildly different from life on Earth. Maybe it's made of silicon! Maybe it has wheels! Or maybe it doesn't. In The Equations of Life, biologist Charles S. Cockell makes the forceful argument that the laws of physics narrowly constrain how life can evolve, making evolution's outcomes predictable. If we were to find something very much like a lady bug eating something very much like an aphid on a distant planet, we shouldn't be surprised. The forms of life are guided by a limited set of rules, and, as a result, there is a narrow set of solutions to the challenges of existence. A remarkable scientific contribution breathing new life into Darwin's theory of evolution, The Equations of Life makes a radical argument about what life can-and can't-be.