Abstract
The course of biological evolution is regarded by many authors as an ascending path toward higher levels of variety, complexity and integration. There are similar but partly conflicting accounts of the nature and causes of this ascending course. With the aim of reaching a unified conception I start by summarily reviewing three notable examples. These are, in their latest presentations, those of Hoffmeyer and Stjernfelt 2015, Szathmáry 2015, and Lane 2015a. Comparison of their commonalities and divergences, combined with further reflections, leads to the following views: 1) cooperation between preexistent traits and processes is the primary determinant in the emergence of evolutionary novelty; 2) cooperation is a triadic relation similar to semiosis ; 3) regulation, the key element of both metabolism and replication, results from the cooperation of energetic and semiotic causation; 4) conceptual generalization and concrete generalization are fruits of cooperation. Conceptual generalizations spring from the cooperation of ideas. I believe these realizations supply essential elements for a unified view of the ascent of biological evolution towards higher levels of organization. Some of these conceptions are also applicable to similar ascending trajectories through the stages of cultural and technological evolution.