Introduction

This volume consists of studies of the relationship between areal diffusion and the genetic development of languages from a number of critical parts of the world. In part, they follow up on some of the ideas in Dixon's essay The Rise and Fall of Languages (1997)-including the punctuated equilibrium model for language development-although in fact they range considerably beyond this. The chapters cover Ancient Anatolia, Modern Anatolia, Australia, Amazonia, Oceania, South-East and East Asia, and Sub-Saharan Africa. We did not feel it necessary to commission specific discussions of South Asia, or North and Central America, or of the Balkans, since there are already excellent studies of these areasin Masica (1976,1991), Sherzer (1973,1976), Campbell, Kaufman, and Smith-Stark (1986), Campbell (1997), and Joseph (1983). In addition, Chapter 2 gives an archaeologist's view on what may have triggered the punctuation of cultural and linguistic periods of equilibrium. The final chapter provides a conspectus on the kinds of linguistic feature that can be borrowed, drawing together the strands from earlier chapters. In this Introduction, we outline the parameters which underlie discussion in the volume, and comment on some of the recurrent conclusions of contributors; for example, the inadequacy of 'family tree' as the only (or as the main) means of describing relationships between languages