title: Complexity, Natural Selection and the Evolution of Life and Humans.
abstract: In this paper, I discuss the concept of complexity. I show that the principle of natural selection as acting on complexity gives a solution to the problem of reconciling the seemingly contradictory notion of generally increasing complexity and the observation that most species don't follow such a trend. I suggest the process of evolution to be illustrated by means of a schematic diagram of complexity versus time, interpreted as a form of the Tree of Life. The suggested model implies that complexity is cumulatively increasing, giving evolution a direction, an arrow of time, thus also implying that the latest emerging species will be the one with the highest level of complexity. Since the human species is the last species evolved in the evolutionary process seen at large, this means that we are the species with the highest complexity. The model implies that the human species constitutes an integral part of organic evolution, yet rendering us the exclusive status as the species of the highest complexity.
authors.affiliation: Department of Education, Uppsala University, Uppsala, Sweden.
authors.forename: Börje
authors.initials: B
authors.lastname: Ekstig
keywords:  Human species; Complexity; Evolution; Language; Natural selection; The Tree of Life