Visual information in the dark: Bioluminescence and perceptual design through evolution

Abstract Bioluminescence offers a powerful framework for understanding how organisms evolve to shape visual information in diverse ways. Complementing studies of colour, transparency and pattern in illuminated environments, bioluminescent systems instead rely on generated light, operate against dark backgrounds and are influenced by distinct energetic and ecological constraints. This review synthesizes how and why four information channels of bioluminescence—wavelength, intensity, spatial pattern and temporal dynamics—diversify during evolution to serve many functions, including predator–prey interactions, species recognition and courtship. These channels each are influenced by mechanisms of emission, environmental mediation and reception, leading to a concept herein called perceptual design : the diversification of visual information systems through evolution. Bioluminescent systems diversify in many ways, with both similarities and differences to diversification of visual information systems in bright environments. In both bright and dim environments, sexual selection likely contributes to diversification of courtship signals. However, whereas courtship and aposematic signals in illuminated settings often diversify in colour space, bioluminescent signals may more often diverge in timing, spatial arrangement and brightness. Emerging evidence also suggests that bioluminescence often originates in nonsexual contexts and later may be co‐opted for courtship. In general, bioluminescent systems complement information systems shaped by ambient light for addressing broad questions in sensory evolution, sexual selection, macroevolutionary dynamics and the origins of biological diversity. Read the free Plain Language Summary for this article on the Journal blog.