Chapter 10: Communication: Origins & Evolution

Communication: Origins & Evolution details how semanticization occurs when evolutionary changes add communicative function to existing traits, often beginning in contexts of conflict or ambivalence, as seen in the classic courtship ceremonies of the Great Crested Grebe or the threat displays of gulls. The text analyzes the opportunistic nature of this evolution, illustrating how diverse biological processes—from the predatory strikes of herons to the excretion of metabolic waste—can be co-opted for signaling. Specific examples include the evolution of nuptial gifts in empidid flies, where prey presentation shifts to the offering of empty silk balloons, and the development of primate facial expressions, where the bared-teeth display is hypothesized to be the homolog of the human smile. The concept of automimicry is introduced, describing how animals, such as female hyenas with pseudopenises or male Haplochromis fish with egg-mimicking fin spots, exploit the signaling systems of their own species for adaptive advantage. Furthermore, the chapter provides a comparative analysis of sensory channels, weighing the trade-offs of chemical communication (pheromones), which offers great range and energetic efficiency but slow transmission, against the high information capacity and flexibility of auditory and visual systems. The discussion extends to specialized modalities like surface-wave communication in water striders and electrical signaling in fish, concluding with the principle that species evolve specific sensory mixes based on phylogenetic constraints and environmental efficiency.