The Unfolding of Language question

Dr. Deutscher surely has done a very great job, and the topic was thoroughly discussed. Asking questions like "how could such or such a phenmenon have emerged today" proved very benefecial in such domains as anthropology and biology and can do, and is doing, the same in linguistics. However, what I could not understand, while reading through the book, is how can we talk about the evolution of langugaes and their development from simple stages to more complex ones without even mentioning, not for a single time, the two phenomna of Pidgins and Creols. Pidgins are contact languages, created when two mutually unintelligible speech communities come into contact with each other. The main characteristics of Pidgins is that they are very simplified languges (phonetically, lexically, morphologically and syntactically), specialized for specific domains (e.g.trading activities) and more importantly mother tongues of no speaker. However and by the time a pidgin gains native speakers it develops to become a ,more or less, full-fledged language within few generations. Discussing this topic of pidgins and creoles could have been of important significance to the book, in my personal opinion, in that it really involves a transition of a more or less me-tarzan stage (do you agree?) to a full fledged language very shortly.