Aphids

Historically the diverse areas of communication research have rarely met, and this factor probably prompted my feeling that the order of chapter delivery in this book was counter-intuitive. Naturally our investigation of any communication system has always been heavily influenced by our own language, and the historical progress of research has broadly progressed 'down' from humans to other mammals, then birds, invertebrates and now bacteria. The editors have favoured such a taxonomic presentation, moving from a chapter discussing bacteria through higher taxa, to three dealing exclusively with humans, which reinforces the view that we understand the least about communication in the simplest organisms. There is a growing recognition, however, that bacteria are excellent (and amenable) models for investigating the evolution of cooperation and here Diggle et al. show that novel evolutionary insights can readily be obtained through the study of bacterial quorum sensing. Their chapter also serves to set the stage for subsequent chapters by providing an invaluable outline of the theoretical evolutionary framework which must be central to any analysis of communication and cooperation. In a later chapter, Matessi et al. discuss the application of network theory to the analysis of social interactions in birds, before chapters on chemical communication, especially its use by social insects where the bewildering variety of signalling compounds highlights the complexity of communication found in sophisticated social groups. There follows a valuable neurobiological insight into honeybee chemical communication from signal perception through to neural processing. Later chapters on the evolution of sexual signals and mate quality signalling lead us to a consideration of genetic aspects in the evolution of signalling systems. Haig examines the common language used when discussing communication in cell-to-cell signalling, where common genomes mean there should be no conflict, and behavioural ecology, where genetic differences make conflicts common. Haig argues that intra-genomic conflict influences signalling within individual organisms. Crespi then examines the role of genomic conflict in human linguistic evolution and shows how the disordered language characteristic of autism brings insights into human social evolution. This fascinating discourse on the pathology of language leads Crespi to contend that " psychosis represents the illness that made us human ". The final three chapters focus on formal treatments of communication. Hurford discusses what is so special about human language and how it might have evolved. Human language fundamentally differs from non-human forms of communication because it is learned, which in large part accounts …