Communication and cooperation in evolutionary biology

Abstract

How can the concepts and results of communication theory aid evolutionary biology? This thesis argues for an explanatory framework, evolutionary communication theory, that interprets and illuminates scientific research into the phenomenon of biological signalling. By expanding the theory beyond the models and goals familiar to Claude Shannon and other engineers, real insight is gained into how strategic interplay between senders and receivers shapes signal form. Furthermore, interpreting artificial and natural signals in terms of sender-receiver teleosemantics demonstrates the explanatory role of relations borne between signals and world affairs. One of the major results of the thesis is a rejection of the orthodox distinction between Shannon and semantic information. While there are at least two useful distinctions to be drawn -- between cues and signals, and between statistical and functional content -- the terminological confusion that gave rise to the phrase `Shannon information' should be put aside for good.

Chapter 1 outlines a way to capture the relationships between signals and other signal-like interactions using a multi-dimensional conceptual space called a hypercube. I argue that sender-receiver teleosemantics is uniquely well suited to capturing those aspects of communication theory that render it a viable mathematical framework for evolutionary biology.

Chapter 2 discusses an early attempt to apply communication theory in evolutionary biology. Haldane & Spurway's informational interpretation of the honeybee waggle dance has recently been criticised on mathematical grounds. These criticisms lend support to scepticism about the relevance of information for evolutionary biology. I argue that the criticisms are themselves mathematically erroneous, so one route to scepticism about information is undercut. Chapter 3 explores a related line of scepticism. It is common in the philosophy of biology to treat the concepts and tools of communication theory as insufficient or irrelevant for analysing semantic content. I argue that the grounds of this supposition are based on misinterpretations of some features of communication theory.

In chapter 4 I reconstruct Millikan's teleosemantics in a causal-modelling setting, highlighting the explanatory role of semantic content. In chapter 5 I respond to objections to the teleosemantic account, including the claim that the theory renders explanations of success that appeal to semantic content circular. I also argue for an interpretation of important features of communication-theoretic models in terms of teleosemantics.

Chapter 6 explores another challenge to applying teleosemantics to biological signals. The theory places emphasis on cooperation between senders and receivers, but biological signals are often fraught with evolutionary conflict. I discuss recent formal work, and argue that prospects for teleosemantics are good. Finally, in chapter 7 I argue that an explanatory framework that draws on communication-theoretic concepts would be beneficial to evolutionary biology. I present case studies of communicative behaviour for which biologists offer explanations that are well interpreted through the principles of communications engineering.