[This review assumes or suggests that you use Amazon's Look Inside feature to see the 14 chapters that are in themselves worthy of being basic, all-you-need-to-know books on each of these subjects.]
The author admits to being both a biologist and a linguist professionally, and this too shows. He makes a continual effort to include vocal and communicative evidence from a wide range of species to show how convergence issues and novel possibilities to test for particular facets offer important leads in the study of human language origins. He also respects and finds lessons from seemingly all linguistic traditions which felt refreshing. In the end of this broad excursion he uses the last three chapters to treat three types of theories on the evolution of language in a way where each of these theory types gets full treatment as subjects like the other chapters. Within these the contributors and the issues were examined for strengths, weaknesses, prospects, and testability possibilities. He gave his own evaluations at the level of issues within each theory type without committing to any particular theory of his own. On the one hand instead of ending up with another particular theory after reading the book, the long immersion in so many aspects and facets of language and human evolution left more an impression that the evolution of language too was a similarly multi-faceted and sweeping event. On the other hand the last chapter/book on musical protolanguage really makes this old hypothesis appealing. [This review assumes or suggests that you use Amazon's Look Inside feature to see the 14 chapters that are in themselves worthy of being basic, all-you-need-to-know books on each of these subjects.]