A century after Herbert Spencer introduced the term “survival of the fittest,” a half-century after Sewall Wright introduced the idea of adaptive fitness landscapes to evolutionary biology, and a quarter-century after Watson and Crick discovered the structure of DNA, two young scientists named Stuart Kauffman and Simon Levin further advanced evolution theory. Their model of evolutionary fitness landscapes incorporated two characteristics shared by both genes and the evolutionary process itself: complexity and interdependence.

A century after Herbert Spencer introduced the term “survival of the fittest,” a half-century after Sewall Wright introduced the idea of adaptive fitness landscapes to evolutionary biology, and a quarter-century after Watson and Crick discovered the structure of DNA, two young scientists named Stuart Kauffman and Simon Levin further advanced evolution theory. Their model of evolutionary fitness landscapes incorporated two characteristics shared by both genes and the evolutionary process itself: complexity and interdependence.