Document Type : Brief Communication
Authors
1 Ionizing and Non-Ionizing Radiation Protection Research Center (INIRPRC), School of Paramedical Sciences, Shiraz University of Medical Sciences, Shiraz, Iran
2 Department of Medical Physics and Engineering, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
Abstract
Human sensory perception operates within narrow and well-defined ranges of mechanical waves (approximately 20 Hz–20 kHz for sound) and electromagnetic radiation (roughly 400–700 nm for visible light). These limits are not arbitrary; rather, they reflect evolutionary trade-offs shaped by ecological relevance, anatomical feasibility, metabolic cost, and the physical properties of the environment. This review examines how such constraints have influenced the evolution of human sensory systems in comparison with those of other species. Human hearing is tuned to frequencies relevant for communication and environmental awareness, supported by anatomical specializations such as the ossicular chain and coiled cochlea. Human vision is similarly restricted to a spectral window that coincides with peak solar irradiance and efficient atmospheric transmission, allowing effective photon detection without the energetic burden of broader spectral sensitivity. Comparative examples from echolocation in bats to infrared sensing in pit vipers demonstrate how sensory systems can diverge dramatically under different ecological pressures. Importantly, the absence of direct sensory perception does not imply the absence of biological interaction with environmental stimuli. In some contexts, organisms exhibit physiological or cellular adaptations rather than sensory awareness. Using populations exposed to elevated natural background radiation as a case study, we evaluate the hypothesis that the lack of evolved sensory organs for ionizing radiation may reflect limited evolutionary advantage for conscious detection rather than biological irrelevance. Overall, sensory systems emerge as energy-efficient solutions for detecting ecologically meaningful signals within strict physical and biological limits.
Keywords
)