Richard J. Watts 
Language in Deep Human History [PDF ebook] 
An Evolutionary Story

Understanding the evolution of language within the context of deep human history requires interdisciplinary work between linguists and scientists from a wide range of academic disciplines (e. g. archaeology, molecular biology, anthropology, genetics, biochemistry, etc.). The book aims to calibrate work on human evolution with current linguistic theory in an attempt to trace out a scientific story of how human language emerged and developed that has plausibility while remaining open to change through new linguistic and non-linguistic research.