From Eternity to Here

by Sean Carroll

From the point of view of natural selection, there are many reasons why a complex, persistent structure might be adaptively favored: An eye, for example, is a complex structure that clearly contributes to the fitness of an organism. But increasingly complex structures require that we turn increasing amounts of free energy into heat, just to keep them intact and functioning. This picture of the interplay of energy and information therefore makes a prediction: The more complex an organism becomes, the more inefficient it will be at using energy for “work” purposes—simple mechanical operations like running and jumping, as opposed to the “upkeep” purposes of keeping the machinery in good working condition. And indeed, that’s true; in real biological organisms, the more complex ones are correspondingly less efficient in their use of energy.