PS: Think of it like this A -> B, B -> C therefore A -> C is all well in good most of the time. A -> B .... Y -> Z therefore A -> Z only really works with math, build a chain that long and it's unlikely for all those steps to be accurate.
If I where to attack the book I could say something like: "In chapter 2 'Chatterboxes' he states humans are the only animal that uses language which is complex issue by it's self. He goes further and says every group of humans in remote areas we encountered have had complex language. He then runs with that line of reasoning. However this ignores not just other animals that use simple forms of language but human ancestors that where close to us anatomically and probably also used language. If homo sapiens's ancestors also used language then you would expect the earliest humans to also use language therefore language would spread from it's origins to all those remote areas vs. being created from scratch in those remote areas."
Now, I could get 10 PHD's to say the same thing and use quotes etc, but what's important is the accuracy of the statement not who says it. http://lesswrong.com/lw/jl/what_is_evidence/
PS: You clearly lack the courage of your convictions to actually leave an argument when you say 'Goodbye'. However, I realize trying to reason with a fool is a waste of time, so best of luck and 'Goodbye'.
PS: You're still an ass, and you don't know what appeal to authority means. We have to be debating and me relying on him to make a point for it to be an appeal to authority. As I clearly indicated I wasn't interested in debating the subject, you can't accuse me of logical fallacies, a point I made previously but you failed to grok because you're an ass.
If you just want a compelling argument: Biology is a vary important component in the creation and evolution of language, because the fine motor control required to say "linguistic" vs "mommy" or "stop" has a lot to do with how languages are learned and evolve. As baby's practice how to say thing babble converts to simple words but in doing so there are pattern as to which sounds are easier to produce and therefore enable them to probe their environment by reproducing. This paralls the evolution of language where the most important and simplist ideas where the first to be communicated and therefore take up the 'root' address space in the language with more complex words and ideas like 'chemist' being tacked on over time.
PS: Sure, it sounds great. But how many assumptions am I stringing together in just those few sentences.