http://popups.lib.uliege.be/1373-5411/index.php?id=944 Index terms fr 0 http://popups.lib.uliege.be/1373-5411/index.php?id=942 The overall information processing capacity of an organism is proposed as a conceptual criterion for its complexity. The apparent tendency of complexity increase during the course of evolution is accounted for in terms of positive feedback mechanisms. Furthermore, the different modes of evolution of biological complexity are identified as: The ongoing appearance of more complex species in case of abundance of resources, pausing of the complexity increase when the limits of the resources are reached in a relatively isolated environment, and the extinction of some of the complex species due to lack of sufficient resources. All arguments concerning the definition of complexity and its non-decreasing character are based on concepts like information processing, maintenance of organisation and the related energy expenditures. As a result of these arguments it is concluded that complex adaptations have a teleonomic nature. Mon, 01 Jul 2024 14:56:01 +0200 Mon, 01 Jul 2024 14:56:13 +0200 http://popups.lib.uliege.be/1373-5411/index.php?id=942