Incidental Emissions, Fortuitous Effects, and the Origins of Communication

In recent years, a small group of animal behaviorists has been calling for a renewed focus on proximate mechanisms in the study of behavioral evolution (Kennedy, 1992; Stamps, 1991). These calls have been made to counter the current view, implicit in most contemporary analyses of animal behavior, that we can understand ultimate causation without worrying about the mechanistic details. As noted by Stamps (1991), however, today's "students of ultimate causation in behavior have begun to 'rediscover' the importance of proximate mechanisms" (p. 342). Specifically, there is a growing realization that proximate mechanisms are not mere details---rather, they vitally shape our understanding of function and of the evolutionary origins of behavior and structure. Communication is an area of animal behavior, we argue, that can especially benefit from a renewed focus on proximate mechanism. This argument is