Toward an Evolutionary Biology of Language
philip lieberman
Harvard university
With the passing of time, the preface to a book that records research that is in progress must grow longer. It is apparent that human language is unique and that some of its biologic bases are species-specific. However, I hope that it will become clear that various attributes of language are present or present in reduced de-gree in other species. I also hope to show that neural mechanisms specific to humans that confer linguistic ability also regulate other aspects of behavior by virtue of their evolutionary history. My own research on the evolution of language and this book owe much to Edmund S. Crelin. I still remember Ed’s words in 1970 as he looked at a cast of the Neanderthal La Chapelle-aux-Saints fossil: “He’s a big baby.” We then started to attempt to track the evolution of hu-man speech, one of the critical elements of human language. Bill Laughlin in 1972 called my attention to the radiographs that track the development of the larynx, pharynx, tongue, and mouth from birth to age twenty years. In 1999 my most demanding critic, my son Daniel, with Robert McCarthy, reevaluated these radiographs and provided a starting point for new quantitative studies of the evolution of the anatomy that allows us to produce the full range of human speech. They found that our vocal anatomy gradually devel-ops, reaching its adult-like form between ages six to eight years. McCarthy and his colleagues have since been able to quantify the ap-praisal of Neanderthal speech capabilities by techniques that place limits on the possible vocal anatomy of Neanderthals and other long-dead hominids. Jeffrey Laitman’s work on the evolution of hu-man vocal anatomy also must be acknowledged.