If “language” were substituted for “organic being” and “natural history” in the excerpt above, Darwin might be expressing the perspective on the origin and evolution of language which we have articulated in this book. We argue that language grows out of a complex of primary human adaptations, including bipedal locomotion, social living, reproduction without an estrous cycle, postnatal epigenesis, postreproductive longevity, and division of labor within the family. In addition, we argue that language grows out of more primitive primate and mammalian neuro-behavioral complexes, including those that govern face-to-face interaction, categorization, and symbolization. Finally, we argue that the key to the transition from primate vocal and visible gesture systems to language (that is, names organized into sentences) is the introduction of iconic, visible gestures at some point in hominid evolution.