Goal-Directedness, Behavior and Evolution: A Philosophical Investigation.

摘要

My dissertation explores the conceptual foundations of the behavioral perspective in biology--that is, what it really means to understand a system (such as an animal) as behaving. Behavior is a somewhat fuzzily defined aspect of living systems that is nevertheless of central importance to a variety of approaches in biology. Behavior has to do with what organisms (and perhaps other biological entities) do, rather than what they are (i.e. behavior is different that anatomy or physiology). It is most obviously a category applied to large, mobile animals like the familiar vertebrates (mammals, birds, reptiles, fish, amphibians) and some invertebrates (insects, arachnids, crustaceans, gastropods and cephalopod mollusks). These are the traditional subjects of behavioral biology. However, in the last few decades, a behavioral approach has been applied to plants, single-celled organisms, and groups of animals such as eusocial insect colonies. Moreover, research projects in behavioral robotics and artificial life apply a behavioral perspective to non-living systems. What does it mean to conceive of a system as behaving? What must a system be like to allow this way of thinking to be fruitful for research? My main contribution to solving this puzzle is the development of a dynamical understanding of goal-directedness . My view of goal-directedness is dynamical in that I understand that notion purely in terms of the causal relations within a system and between the system and its environment, rather than in terms of primitively intentional notions, or in terms of evolutionary history. Previous attempts at developing a dynamical understanding of goal-directedness have foundered, but I present a robust solution to the problems that hindered them. I also demonstrate how the dynamical understanding of goal-directedness functions conceptually in contemporary biological research on animal behavior, and how it is crucial for understanding the 'major transitions in evolution', events in which the evolutionary process itself is reorganized, and new levels of structure emerge in the living world.