Tonogenesis and the Evolution of Tone Systems

This chapter provides an overview of what is currently known about tonogenesis, the development of lexical tone, and about the evolution of tone in languages that are already tonal. We begin with a critical overview of classical models of tonogenesis and survey less common sources of tonal development, with a systematic discussion of their phonetic underpinnings. We then review the phonetic, structural, and contact‐related factors that may initiate the transphonologization of laryngeal contrasts into contrastive tones. We finally discuss current models of tone drift and outline what is known about the development of tonal alternations, tone mergers, and tonoexodus, the loss of tone.