Since the time of Charles Darwin, complexity has most often been regarded as a typical result of evolutionary processes, both in popular and scholarly literature. Complexity is clearly not a necessary result of natural selection, the primary process for evolutionary change that simply refers to the reduction of variation according to the differential replicability of an entity's characteristics. Nevertheless, the history of life on earth is still seen as the story of increasingly complex organisms, a story with close parallels in discussions of the evolution of other systems such as human sociocultural formations. Accordingly, considerable scholarly effort is expended on explaining how or even if evolutionary theory, in either its classic or contemporary forms, can explain why change seems so closely linked with increasing complexity.
These issues, of course, beg the question of what exactly we mean by the term “complexity.” A 1995 article in Scientific American presented a list, compiled by Seth Lloyd, of over 30 different ways that the concept has been used in a variety of disciplines (Horgan 1995). With definitions ranging from “the amount of entropy in a system” to “the amount of computer memory required to describe a system, ” the word “complexity” has increasingly become a symbol of uncertainty and incomprehension, so much so that many people consider it to mean “something too complicated to understand” or “something we have no means of understanding” (Segraves 1982:288).
Dictionaries are not particularly helpful, usually defining complexity as “the state of being complex” but also offering “intricacy, entanglement”