Okay. A Homo Erectus, a Neanderthal, and a Human Being are walking down the street. Upright, loping gait, strolling down Mass. Ave. From the neck down they all look pretty much the same. Up top, though, at the head, the human looks markedly different. Smaller brow, face set back underneath the forehead, shorter face, much smaller jaw, in fact drooling a little from having just visited the dentist to get rid of a couple of wisdom teeth that had no room to grow. Oh, this isn’t a joke. It’s the evolution of the human head. Or, more specifically, it’s The Evolution of the Human Head, by Daniel E. Lieberman.
Lieberman is the chair of Harvard’s recently formed department of human evolutionary biology, and his new book is the culmination of years and years of research into the development of the human head. Why does the human head look the way it does, so different from that of all other mammals? How is it that something so incredibly complex, that controls so many interrelated functions, has been so adaptable? How does the organ through which we eat, hear, smell, sense, think, and speak manage to grow from the size of a grape to the size of a honeydew? What behaviors are still shaping the human head, faster than could be accounted for by natural selection? And what can the evolution of the human head tell us about the rest of the human body and how we evolved as a species?
As Lieberman explains in the video below, all of these questions led him to write this weighty new entry into the literature of evolutionary biology.