Human Aquatic Color Vision

Many human physiological and behavioral features could possibly be explained as semi-aquatic adaptations in the remote past. However, aspects of human perception and cognition have rarely been considered in this light. In this chapter, human color vision will be discussed at two levels.

At the physiological level, visual pigments of retinal cone/rod cells, being essential to color vision, are compared among humans, their closest primate relatives, and terrestrial as well as aquatic mammals. Also the cause of human color blindness is discussed.

At the cultural level, the mystery of ‘fuzzy’ color terms like grue (green-or-blue) in many world languages is discussed, and we propose a new model based on two arguments: each color term actually corresponds to a naturally occurring color, and the ‘ fuzzy’ terms were produced in a semi-aquatic primitive life since the dawn of human language.

Keywords: Human evolution, aquatic adaptations, color vision, color blindness, linguistic color terms