The Ecology of Humans (15-24) Evolution of Sight continued 4


Marsupials are trichromats. Some insects, including the honeybee, are also trichromats, but are receptive to a higher wavelength range: ultraviolet, blue, and green, instead of blue, green and red.

Some cephalopods, including certain octopi, can produce vibrant color displays that adroitly match their desires, whether blending into the environment to disguise themselves or in acts of bodacious mimicry. This remarkable color shifting is achieved with eyes that are ostensibly color-blind.

Mental color construction in cephalopods is achieved via odd vision hardware: an off-axis u-shaped pupil that affords chromatic aberration, where prismatic colors are perceived because different light wavelengths come into focus at different distances behind the lens. The resultant visual imagery is not sharp but does give a sense of color. There may be unknown means for mental sharpening.