The Selfish Gene, Richard Dawkins suggests that genetic evolution is just one example of an evolutionary system. He identifies the essential elements of the category---discrete replicators, variability and differential reproduction---and proposes that any system that has these elements displays similar behavior, including complexity without design. As another example of an evolutionary system, he proposes memes, which are thoughts or behaviors that are ``replicated'' by transmission from person to person. As memes compete for the resource of human attention, they evolve in ways that are similar to genetic evolution.

Stefano Rocca Parmenides: "A reductionist model describes a system by descri...: http://allendowney.blogspot.it/2012/02/self-organized-criticality-and-holistic.html?spref=tw