Sound on the rebound: Bringing form and function back to the forefront in understanding nonhuman primate vocal signaling

Scientists often posit an intimate connection between form and function, a conceptual approach that plays a central role in evolutionary anthropology. Functional morphologists and paleontologists, for example, routinely connect structure and function in exploring how skeletal features of fossils reflect adaptations to particular motor demands. Archeologists' reconstructions of early hominid life-ways are guided by functional interpretations of material remains, while both primatologists and human ecologists use structural properties of the environment to understand important aspects of social organization. Although comparisons to human language were characteristic of early work on nonhuman primate vocal behavior as well, during the last two or more decades they also have become dominent in the anthropological subfield of acoustic primatology. This strategy has paid dividends by, for example, generating widespread interest in primate signaling and catalyzing a variety of fruitful empirical studies. However, it also creates conceptual worries, particularly in the teleology inherent in using complex linguistic phenomena from humans as models for simpler vocal processes in nonhumans.